News: Mikroteknologi och nanovetenskap related to Chalmers University of TechnologyFri, 11 Sep 2020 10:32:53 +0200 of Advance Award for wireless centre collaboration<p><b>​Collaboration is the key to success. Jan Grahn and Erik Ström, who have merged two Chalmers competence centres, GigaHertz and ChaseOn, to form a consortium with 26 parties, know this for sure. Now they receive the Areas of Advance Award 2020 for their efforts.</b></p>​<span style="background-color:initial">A competence centre is a platform for knowledge exchange and joint projects. Here, academia and external parties gather to create new knowledge and innovation. The projects are driven by need, and can be initiated from industry – who have a problem to solve – or from the research community, as new research results have generated solutions that may be applied in industry.</span><h2 class="chalmersElement-H2">Stronger as one unit</h2> <div>The competence centre GigaHertz focuses on electronics for high frequencies, while ChaseOn focuses on antenna systems and signal processing. They overlap in microwave technology research, which is relevant for communication and health care, as well as defense and space industry. And even if some areas differ between the two centres, numerous points of contact have been developed over the years. The two directors – Jan Grahn, Professor at Microtechnology and Nanoscience, and Erik Ström, Professor at Electrical Engineering – saw that close collaboration would result in obvious advantages. In 2017, the two centres therefore formed a joint consortium, bringing together a large number of national and international companies.</div> <div>“Formally, we are still two centres, but we have a joint agreement that makes it easy to work together”, says Erik Ström.</div> <div>“For Chalmers, it is a great strength that we are now able to see the whole picture, beyond departmental boundaries and research groups, and create a broad collaboration with the companies. This is an excellent example of how Chalmers can gather strength as one unit”, says Jan Grahn.</div> <h2 class="chalmersElement-H2">Multiplicity of applications</h2> <div>Technology for heat treatment of cancer, detection of foreign objects in baby food, antenna systems for increased traffic safety, components to improve Google’s quantum computer, 5G technology and amplifiers for the world’s largest radio telescope… The list of things that have sprung from the two competence centres is long. The technical development has, of course, been extreme; in 2007, as GigaHertz and ChaseOn were launched in their current forms, the Iphone hit the market for the very first time. Technology that today is seen as a natural part of everyday life – such as mobile broadband, now almost a necessity alongside electricity and water for most of us – was difficult to access or, at least, not to be taken for granted.</div> <div>The companies have also changed, which is noticeable in the flora of partners, not least for GigaHertz.</div> <div>“In the early 2000s, when our predecessor CHACH centre existed, the collaboration with Ericsson was dominant. Today, we collaborate with a much greater diversity of companies. We have seen an entrepreneurial revolution with many small companies, and even though the technology is basically the same, we are now dealing with a multiplicity of applications”, says Jan Grahn.</div> <div>As technology and applications developed and changed, the points of contact between the two centres grew, and this is also what initiated the merger:</div> <div>“When we started, in 2007, we were competing centres. The centres developed completely independently of each other, but have now grown into one. The technical convergence could not be ignored, we simply needed to start talking to each other across competence boundaries – which in the beginning was not so easy, even though today we view this as the obvious way forward”, says Erik Ström.</div> <h2 class="chalmersElement-H2">Research to benefit society</h2> <div>The knowledge centres are open organisations, where new partners join and collaborations may also come to an end. Several companies are sometimes involved together in one project. Trust and confidence are important components and take time to build. One ground-rule for activities is the focus on making research useful in society in the not too distant future.</div> <div>Chalmers Information and Communication Technology Area of Advance can take some of the credit for the successful collaboration between GigaHertz and ChaseOn, according to the awardees.</div> <div>“Contacts between centres were initiated when I was Director of the Area of Advance”, says Jan Grahn.</div> <div>“The Areas of Advance show that we can collaborate across departmental boundaries, they point to opportunities that exist when you work together.”</div> <h2 class="chalmersElement-H2">They believe in a bright future</h2> <div>The competence centres are partly financed by Vinnova, who has been nothing but positive about the merger of the two. Coordination means more research for the money; partly through synergy effects and partly by saving on costs in management and administration.</div> <div>The financed period for both GigaHertz and ChaseOn expires next year. But the two professors are positive, and above all point to the strong support from industry.</div> <div>“Then, of course, we need a governmental financier, or else we must revise the way we work. I hope that Vinnova gives us the opportunity to continue”, says Erik Ström.</div> <div>“The industry definitely wants a continuation. But they cannot, and should not, pay for everything. If they were to do so, we would get a completely different type of collaboration. The strength lies in sharing risks in the research activities by everyone contributing funds and, first and foremost, competence”, says Jan Grahn.</div> <h2 class="chalmersElement-H2">“Incredibly fun”</h2> <div>Through their way of working, Erik Ström and Jan Grahn have succeeded in renewing and developing collaborations both within and outside Chalmers, attracting new companies and strengthening the position of Gothenburg as an international node for microwave technology. And it is in recognition of their dynamic and holistic leadership, that they now receive the Areas of Advance Award.</div> <div>“This is incredibly fun, and a credit for the entire centre operation, not just for us”, says Erik Ström.</div> <div>“Being a centre director is not always a bed of roses. Getting this award is a fantastic recognition, and we feel great hope for the future”, concludes Jan Grahn.<br /><br /><div><em>Text: Mia Malmstedt</em></div> <div><em>Photo: Yen Strandqvist</em></div> <br /></div> <div><strong>The Areas of Advance Award</strong></div> <div>With the Areas of Advance Award, Chalmers looks to reward employees who have made outstanding contributions in cross-border collaborations, and who, in the spirit of the Areas of Advance, integrate research, education and utilisation. The collaborations aim to strengthen Chalmers’ ability to meet the major global challenges for a sustainable development.<br /><br /></div> <div><a href="/en/centres/ghz/Pages/default.aspx">Read more about GigaHertz centre</a></div> <div><a href="/en/centres/chaseon/Pages/default.aspx">Read more about ChaseOn centre​</a></div> <div>​<br />Areas of Advance Award 2019: <a href="/en/news/Pages/Areas-of-Advance-Award-given-to-research-exploring-the-structure-of-proteins.aspx">Areas of Advance Award for exploring the structure of proteins​</a></div> Thu, 10 Sep 2020 08:00:00 +0200 atoms merge quantum processing and communication<p><b>​Researchers at Chalmers University of Technology in Sweden and MIT in the US, among others, have demonstrated a new quantum-computing architecture that makes it possible to both perform quantum computations and communicate quantum information between distant parts of the quantum processor, all with low losses. The results were recently published in the renowned scientific journal Nature.</b></p><img src="/SiteCollectionImages/Institutioner/MC2/News/anton_IMG_8889_350x305.jpg" alt="Picture of Anton Frisk Kockum." class="chalmersPosition-FloatRight" style="margin:5px" />&quot;We showed that quantum bits can communicate through a waveguide without the quantum information being lost&quot;, says Anton Frisk Kockum (to the right), researcher at the Applied Quantum Physics Laboratory at the Department of Microtechnology and Nanoscience – MC2, at Chalmers, and one of the authors of the article.<br /><br />A challenge for scaling up quantum computers is to enable communication between quantum bits (qubits) that are far apart. Coupling qubits to a long waveguide is usually detrimental, since it provides a channel through which quantum information can leak out. The solution the researchers found was to use “giant atoms”, a new regime of light-matter interactions.<br /><br />“Natural atoms are usually much smaller than the wavelength of the light they interact with. However, an experiment in the group of Professor Per Delsing at Chalmers in 2014 showed that an artificial atom made from superconducting circuits can connect to a waveguide at multiple points spaced wavelengths apart. When calculating how two such giant atoms would behave, we found that interference effects due to emission from the multiple coupling points could prevent the atoms from decaying into the waveguide, but still allow them to talk to each other via the waveguide. This was now demonstrated in the experiment carried out at MIT”, explains Anton Frisk Kockum.<br /><br />The researchers used the interference effects of the giant atoms to demonstrate both that the individual atoms could be protected from losing quantum information into the waveguide and that the two atoms could be entangled, with 94% fidelity, through their protected interaction via the waveguide. <br /><br />This is the first time that anyone has even reported a number for the fidelity of a two-qubit operation with qubits strongly coupled to a waveguide, since the fidelity for such an operation would be low if the qubits were not giant. The ability to perform high-fidelity quantum-computing operations on qubits coupled to a waveguide creates exciting new opportunities. <br />“It is now possible to prepare a complex quantum state in the qubits, and then quickly adjust the interference effect in the giant atoms to turn on the coupling to the waveguide and emit this quantum state as photons that can travel a long distance”, says Anton Frisk Kockum.<br /><br />The study is a collaboration between scientists from Chalmers (the theoretical part), MIT, and the research institution RIKEN in Japan. From Chalmers, Anton Frisk Kockum contributed.<br /><br />The work was partly supported by the Knut and Alice Wallenberg Foundation and The Swedish Research Council. The experiments were performed at the Research Laboratory for Electronics at MIT.<br /><br />Photo of Anton Frisk Kockum: Michael Nystås<br />Illustration: Philip Krantz, Krantz NanoArt<br /><br /><strong>Contact:</strong><br />Anton Frisk Kockum, Researcher, Applied Quantum Physics Laboratory, Department of Microtechnology and Nanoscience – MC2, Chalmers University of Technology,<br /><br /><strong>Read the article in Nature &gt;&gt;&gt;</strong><br /><a href="">Waveguide quantum electrodynamics with superconducting giant artificial atoms</a><br /><br /><a href="">Read more about the research project</a> &gt;&gt;&gt;<br /><br /><strong>Further reading &gt;&gt;&gt;</strong><br /><a href="">Propagating phonons coupled to an artificial atom</a>. Gustafsson et al., Science 346, 207 (2014)<br /><a href="">Decoherence-Free Interaction between Giant Atoms in Waveguide Quantum Electrodynamics</a>. Kockum et al., Physical Review Letters 120, 140404 (2018)<br /><br /><a href="">Press release from MIT</a> &gt;&gt;&gt;Wed, 02 Sep 2020 09:00:00 +0200 effect in graphene with topological topping demonstrated<p><b>​Researchers at Chalmers University of Technology, Sweden, have demonstrated the spin-galvanic effect, which allows for the conversion of non-equilibrium spin density into a charge current. Here, by combining graphene with a topological insulator, the authors realize a gate-tunable spin-galvanic effect at room temperature. The findings were published in the scientific journal Nature Communications.</b></p>“We believe that this experimental realization will attract a lot of scientific attention and put topological insulators and graphene on the map for applications in spintronic and quantum technologies,” says Associate Professor Saroj Prasad Dash, who leads the research group at the Quantum Device Physics Laboratory (QDP), the Department of Microtechnology and Nanoscience – MC2.<br /><br />Graphene, a single layer of carbon atoms, has extraordinary electronic and spin transport properties. However, electrons in this material experience low interaction of their spin and orbital angular moments, called spin-orbit coupling, which does not allow to achieve tunable spintronic functionality in pristine graphene. On the other hand, unique electronic spin textures and the spin-momentum locking phenomenon in topological insulators are promising for emerging spin-orbit driven spintronics and quantum technologies. <img src="/SiteCollectionImages/Institutioner/MC2/News/dmitrii_2020_350x305.jpg" alt="Picture of Dmitrii Khokriakov." class="chalmersPosition-FloatRight" style="margin:5px" /><br />However, the utilization of topological insulators poses several challenges related to their lack of electrical gate-tunability, interference from trivial bulk states, and destruction of topological properties at heterostructure interfaces. <br />“Here, we address some of these challenges by integrating two-dimensional graphene with a three-dimensional topological insulator in van der Waals heterostructures to take advantage of their remarkable spintronic properties and engineer a proximity-induced spin-galvanic effect at room temperature,” says Dmitrii Khokhriakov (to the right), PhD Student at QDP, and first author of the article.<br /><br />Since graphene is atomically thin, its properties can be drastically changed when other functional materials are brought in contact with it, which is known as the proximity effect. Therefore, graphene-based heterostructures are an exciting device concept since they exhibit strong gate-tunability of proximity effects arising from its hybridization with other functional materials. Previously, combining graphene with topological insulators in van der Waals heterostructures, the researchers have shown that a strong proximity-induced spin-orbit coupling could be induced, which is expected to produce a Rashba spin-splitting in the graphene bands. As a consequence, the proximitized graphene is expected to host the spin-galvanic effect, with the anticipated gate-tunability of its magnitude and sign. However, this phenomenon has not been observed in these heterostructures previously.<br />“To realize this spin-galvanic effect, we developed a special Hall-bar-like device of graphene-topological insulator heterostructures,” says Dmitrii Khokhriakov. <br /><br /><img src="/SiteCollectionImages/Institutioner/MC2/News/saroj_prasad_dash_350x305.jpg" alt="Picture of Saroj Dash." class="chalmersPosition-FloatLeft" style="margin:5px" />The devices were nanofabricated in the state-of-the-art cleanroom at MC2 and measured at the Quantum Device Physics Laboratory. The novel device concept allowed the researchers to perform complementary measurements in various configurations via spin switch and Hanle spin precession experiments, giving an unambiguous evidence of the spin-galvanic effect at room temperature. <br />“Moreover, we were able to demonstrate a strong tunability and a sign change of the spin galvanic effect by the gate electric field, which makes such heterostructures promising for the realization of all-electrical and gate-tunable spintronic devices,” concludes Saroj Prasad Dash (to the left).<br /><br />The researchers acknowledge financial support from the European Union Graphene Flagship, Swedish Research Council, VINNOVA 2D Tech Center, FlagEra, and AoA Materials and EI Nano program at Chalmers University of Technology.<br /><br />Illustration: Dmitrii Khokhriakov<br />Photo of Saroj Prasad Dash: Oscar Mattsson<br />Photo of Dmitrii Khokhriakov: Private<br /><br /><a href="">Read the full paper in Nature Communications</a> &gt;&gt;&gt;<br /><br />References<br />1. D. Khokhriakov, A.M. Hoque, B. Karpiak, &amp; S.P. Dash, Gate-tunable spin-galvanic effect in graphene-topological insulator van der Waals heterostructures at room temperature, Nature Communications. 11, 3657 (2020).<br />2. A. Dankert, P. Bhaskar, D. Khokhriakov, I. H. Rodrigues, B. Karpiak, M. V. Kamalakar, S. Charpentier, I. Garate, S.P. Dash. Origin and evolution of surface spin current in topological insulators. Phys. Rev. B 97, 125414 (2018).<br />3. A. Dankert, J. Geurs, M. V. Kamalakar, S. Charpentier, &amp; S.P. Dash, Room Temperature Electrical Detection of Spin Polarized Currents in Topological Insulators. Nano Letters 15, 7976–7981 (2015).<br />4. D. Khokhriakov, A. W. Cummings, K. Song, M. Vila, B. Karpiak, A. Dankert, S. Roche, S. P. Dash, Tailoring emergent spin phenomena in Dirac material heterostructures. Science Advances. 4, eaat9349 (2018).<br />Thu, 27 Aug 2020 09:00:00 +0200 by curiosity after 50 years<p><b>​Kjell Jeppson rather looks forward than back in time. It is now 50 years since he stepped in through the gates as a doctoral student at Chalmers. As a pensioner, he keeps up with orienteering and supervision. &quot;I&#39;m still driven by curiosity,&quot; he says.</b></p><img src="/SiteCollectionImages/Institutioner/MC2/News/kjeppson_IMG_8794_350x305.jpg" alt="Picture of Kjell Jeppson." class="chalmersPosition-FloatRight" style="margin:5px" />We meet at Kemigården on a June day which will prove to be one of the hottest of the year. Some seagulls are screaming around above us. Kjell Jeppson is comfortably dressed in cotton trousers, short-sleeved shirt, vest and a straw hat. He looks relaxed. <div>&quot;An advantage of being a professor emeritus is that you have no other duties, but can sit for a whole day and talk to a doctoral student,&quot; he says.</div> <div> </div> <div>The Corona pandemic has of course affected Kjell Jeppson just like everyone else this spring. He tries to be careful to pay attention to the authorities' recommendations. Recently, he celebrated his 73rd birthday. It was a different celebration:</div> <div>&quot;When the children come with their partners, I say: Strict rules! No one enters! We keep our distance! But just like that, everyone is indoors anyway, it's hard to be careful! But we have a large terrace where we could be in the end,&quot; says Kjell.</div> <div> </div> <div>He and the family have stayed healthy during the crisis.</div> <div>&quot;When you see the reports on TV with those who have been really sick, you think that &quot;you do not want to be in that situation&quot;.&quot;</div> <div>Kjell has stayed away from Chalmers, where he has a workplace in the Terahertz and Millimetre Wave Laboratory in the MC2 building.</div> <div>&quot;It feels a bit empty inside, but I have had very close contact with one of the doctoral students. We have spent over three months full time writing an article on three pages! Now it is submitted for evaluation,&quot; Kjell says.</div> <div> </div> <div>He is a man who lives in the present and does not want to dwell too much in the past, but he offers some puzzle pieces during our conversation. Born in 1947, grew up in Guldheden with parents and younger sister, then a student at Landalaskolan, then high school followed by a Master of Science degree in electrical engineering at Chalmers from 1966. An obvious choice.</div> <div>&quot;We went by tram or walked past Chalmers every day. &quot;That's where I should start,&quot; I thought. It was always Chalmers that it came to. There was a small meetinghouse where my sister attended a dance school at the same spot where the student union building lies today.&quot;</div> <div> </div> <div>Chalmers was an important part of Kjell's everyday life, in fact throughout his entire childhood. In high school he attended a class where 26 students out of 29 started at Chalmers eventually.</div> <div>&quot;It was quite purposeful,&quot; he says with a smile.</div> <div> </div> <div>He describes Guldheden as a nice area to grow up in and praises the city planners:</div> <div>&quot;It was a valley with buildings on both sides, a small school, a football field that was washed every winter so we could go skating, and completely car-free,&quot; he says.</div> <div> </div> <div>Mom was a housewife and sewed all the family's clothes. Kjell remembers how all the women in the area queued at the convenience store when the new style patterns were released every spring. New fabrics were bought, summer dresses were sewn.</div> <div>&quot;It was a little fuss. Large fabrics were laid on the table and the tissue paper was fixed on them with needles. It was a different life and a small world.&quot;</div> <div> </div> <h3 class="chalmersElement-H3">Where does your technology interest come from?</h3> <div>&quot;It's probably from my father. He had trained as a high school engineer at &quot;Chalmers lägre&quot;, and was in charge of a mechanical workshop at SKF. Dad was a pure practitioner who always built small useful things from different parts. Suddenly he had built a screwdriver! He did so with everything. There was no doubt that we would replace silencers and water pumps in the car itself. But I probably never became as practical as he,&quot; says Kjell.</div> <div> </div> <div>In May, 50 years ago, he began his doctoral studies at the then Department of Electron Physics, more or less hand-picked by the legendary professor Torkel Wallmark. During his doctoral studies, he spent a year at Rockwell International in Los Angeles. The dissertation took place in 1977 with the thesis &quot;Design and characterization of MIS devices&quot;. As a curiosity, it can be mentioned that the thesis's main article is still cited by other researchers 30-40 times a year.</div> <div>&quot;We speculated a little about instability in mos circuits, and were a bit out on the limb, but it turned out to be pretty good. We must have been at the forefront!&quot;</div> <div> </div> <div><img src="/SiteCollectionImages/Institutioner/MC2/News/kjeppson_IMG_8788_350x305.jpg" alt="Picture of Kjell Jeppson." class="chalmersPosition-FloatLeft" style="margin:5px" />Kjell Jeppson remained at Chalmers, now as an assistant professor, and later a senior lecturer and associate professor before being promoted to professor of microelectronics in 1996.</div> <div>&quot;Microelectronics was on the rise then, and national microelectronics programs were started. We received a large grant and were able to build an education lab, &quot;kretslabbet&quot;. It was a milestone that allowed us to start training and get real circuits made in a technology that had been inaccessible before.&quot;</div> <div> </div> <div>Retiring was also a milestone for Kjell. Contrary to all expectations, he was invited to be a visiting professor at Shanghai University in China.</div> <div>&quot;I spent four shorter periods in Shanghai and managed to supervise a doctoral student both on site and then remotely for a Chinese PhD. Her name is Bao Jie and she is currently a postdoc in Canada. It was a new experience to connect with young people in China,&quot; says Kjell.</div> <div> </div> <h3 class="chalmersElement-H3">What's your driving force?</h3> <div>&quot;Curiosity. I was also given the opportunity to change research fields from silicon components to carbon nanotubes and graphene. Graphene has such good heat-equalizing properties. We used it to spread heat on chip surfaces and in this way get better circuits. When we had done that, we thought that you can actually make transistors of graphene. That means I'm really back to where I started, and doing the same things we did then but with significantly better tools, like laser printers instead of inky xy printers and graphs hand drawn with ruler and curve template on millimeter paper. The circle is closed.&quot;</div> <div> </div> <div>The great leisure interest since 30 years is orienteering. Kjell and his wife travel around the world and let the locations of the races control where they end up. Some recent examples are New Zealand, Switzerland, Estonia, Latvia, Lithuania, Belarus, Hungary and Croatia. In February every year there are training camps in Portugal.</div> <div>&quot;Last year I ran 97 competitions! Now it is less races to run. We just got home from Portugal before the big shutdowns.&quot;</div> <div>&quot;The travel destinations is a little different. We do not go to the big cities but end up in Castelo de Vide or some other small border village where you can get a cup of coffee for ten crowns at a cozy café, or a glass of wine for a euro,&quot; Kjell says.</div> <div> </div> <div>Text and photo: Michael Nystås</div>Wed, 08 Jul 2020 06:00:00 +0200 exclusive student conference in quantum technology<p><b>​Participants from some 30 countries are expected to attend Berlin when the Quantum Future Academy 2020 (QFA2020) is organized on 1-7 November. The event is coordinated from Chalmers with Professor Göran Wendin at the forefront. Now he is chasing top Swedish students for the conference.</b></p><img src="/SiteCollectionImages/Institutioner/MC2/News/GoranWendin_171101_01_350x305.jpg" alt="Picture of Göran Wendin" class="chalmersPosition-FloatRight" style="margin:5px" />Göran Wendin, to the right, is one of the driving forces within the Wallenberg Centre for Quantum Technology (WACQT), which is led by Chalmers and aims to build a Swedish quantum computer within twelve years. At the moment, however, he is fully busy with the QFA2020 management.<br />&quot;It is an extensive job with a lot of work, but also a lot of fun,&quot; he says in a pause.<br /><br />The assignment comes directly from the German research institute VDI Technologiezentrum [VDITZ] in Düsseldorf, which is the headquarters of the EU's research flagship on quantum technology, worth one billion euros, launched in autumn 2018.<br /><br />The idea of ​​QFA2020 is to offer European top students in the field of quantum technology an opportunity to gain new knowledge and new contacts in order to develop future commercial applications of the technology.<br />Similar events have been held four times before, then at the national level in Germany and France. Now, QFA is opening up and turning it into a major European education conference with participants from 30 countries.<br />&quot;One of the aims is to raise the understanding of quantum technology as a matter for Europe as a whole. We want to help create a sustainable network of young researchers,&quot; says Göran Wendin.<br /><br />Each participating country selects two students during the late summer who can travel to Germany completely free of charge in November. Travel, accommodation and living are fully reimbursed.<br /><br />QFA2020 will take place in Berlin. However, Göran Wendin points out that the organizers are closely following the development of the corona pandemic, and that all safety procedures will be followed.<br />&quot;All participants will receive detailed information in good time about any changes,&quot; he says.<br /><br />The application is open until 24 July for all interested students at the bachelor's or master's level with basic knowledge in quantum mechanics. In Sweden, the winners will be presented at a digital workshop at Chalmers in mid-September, where all applicants will present their ideas.<br /><br />The conference week in Berlin in November has a packed content. It will include study visits to companies and research laboratories, lectures, meetings with researchers, politicians and entrepreneurs, workshops and even cultural activities.<br />&quot;We can promise an exciting and exclusive week in Berlin,&quot; concludes Göran Wendin.<br /><br />Text: Michael Nystås<br />Photo: Johan Bodell<br /><br /><strong>Contact:</strong><br />Göran Wendin, Professor, Quantum Technology Laboratory, Wallenberg Centre for Quantum Technology (WACQT), Department of Microtechnology and Nanoscience <span>–<span style="display:inline-block"></span></span> MC2, Chalmers,<br /><br /><div><span><strong>Read more about Quantum Future Academy 2020 (QFA2020) &gt;&gt;&gt;</strong><br /><a href="/en/centres/wacqt/qfa2020"></a> and also<br /><a href=""></a> <br /><br /><strong><a href="/en/centres/wacqt">Read more about Wallenberg Centre for Quantum Technology (WACQT)</a> &gt;&gt;&gt;</strong><br /><br /><a href="">Läs mer om Read more about the EU flagship in quantum technology </a>&gt;&gt;&gt;<span style="display:inline-block"></span></span><br /></div>Fri, 03 Jul 2020 09:00:00 +0200 star sharpens her skiing with technology from Chalmers<p><b>​Power meters integrated in a ski-pole handle from Chalmers will contribute to skier Lina Korsgren&#39;s third victory in Vasaloppet. &quot;The pole and the power measurement can help me improve one more step,&quot; she says in a news feature on SVT Sport on 16 June.</b></p><img src="/SiteCollectionImages/Institutioner/MC2/News/johan_lina_375x500.jpg" alt="Picture of Johan and Lina." class="chalmersPosition-FloatLeft" style="margin:5px" />The new handle has sensors that measure the power while poling and can be mounted on any pole. Lina Korsgren has now started to use the invention in her training:<br />&quot;The handle is a little thicker than a regular handle, but I just see it as an advantage because then you do not have to hold the pole as hard. It is positive with less strain on the elbows, but otherwise it feels just as usual&quot;, she tells SVT Sport.<br /><br />The data from the handles is sent to software for analysis down to fractions of a single poling. It makes it possible to adjust the really small details of the ride. Lina Korsgren's trainer, former elite cyclist Mattias Reck, says on SVT Sport:<br /><div>&quot;Lina is already incredibly good, but that means if she is to get even better, there are little things you can work on. Power measurement is really such a next step. I am absolutely convinced that we will make her even stronger.&quot;</div> <div><br /></div> <div><br /><br /></div> <div><span><em><br />Johan Högstrand, CEO of Skisens AB, and skier Lina Korsgren </em><br /><em>with the ski poles whose handle is based on Chalmers </em><br /><em>technology. Photo: Mattias Reck</em></span><br /></div> <br />The background to the handle is a master's thesis, which was supervised in 2016 by Dan Kuylenstierna, associate professor at the Microwave Electronics Laboratory at the Department of Microtechnology and Nanoscience – MC2 – at Chalmers, and postdoctoral student Szhau Lai at the same department.<br />&quot;Szhau Lai, who had recently defended his thesis, showed a keen interest in sensors and embedded electronics. Through the Area of Advance Materials Science and Chalmers Sports &amp; Technology he was given the opportunity to work with sensor solutions and underwater communication for swimming. The idea behind the ski power meter came as a spin-off from this work&quot;, says Dan Kuylenstierna.<br /><br />Johan Högstrand, who studied automation and mechatronics, was one of the students. The group ou students also included Henrik Gingsjö, Jeanette Malm, Theo Berglin, Mathias Tengström and Marcus Bengths.<br /><br /><img src="/SiteCollectionImages/Institutioner/MC2/News/dan_2015_350x305.jpg" alt="Photo of Dan Kuylenstierna." class="chalmersPosition-FloatRight" style="margin:5px" />After the end of the thesis work, the students continued to develop the handle with support from Vinnova. In 2017, they took the victory in the business development competition Chalmers Ventures Startup Camp. This helped them to establish the company Skisens AB, with Johan Högstrand as CEO. Dan Kuylenstierna is co-owner and co-founder:<br />&quot;With the large variations in the skiing conditions, power measurement is necessary to estimate performance. It is our conviction that in the long term it will be more important for skiiing than it currently is in cycling. The great importance of technical skills in cross-country skiing also makes it important to measure in the field under realistic conditions&quot;, says Dan (picture to the right).<br /><br />One who early snatched up the rumor about the company is the former coach of the Swedish national biathlon team (Svenska Skidskytteförbundet), Wolfgang Pichler. Pichler immediately said that &quot;power measurement is a revolution for skiing&quot; and got the team to invest in a collaboration with Skisens. Dan Kuylenstierna emphasizes the importance of this work and sees it as crucial for the company’s position today.<br />&quot;People like Wolfgang, who dare to invest in what is new even if the benefit lies several years into the future, are extremely valuable&quot;, he says.<br /><br />Now the company has arrived at a product that opens to a wider market with more partners. Recently, they have thus started to collaborate with Lina Korsgren's team, Team Ramudden, where Mattias Reck is hired as head coach via the company Guided Heroes.<br />&quot;It's very exciting to have the opportunity to apply my experience and knowledge in a new sport. In ski sports you often only have heart rate monitors, but with power meters in the sticks you can see how hard you press in every second, it gives completely new opportunities&quot;, says Mattias Reck in a press release.<br /><br />Dan Kuylenstierna is also Deputy Director of <a href="/en/centres/sportstechnology">Chalmers Sports &amp; Technology</a>, a venture that links academic research and sport in a number of projects. In the fall, he will lead the new course &quot;Digitalization in Sports&quot; within the framework of Chalmers new training venture <a href="">Tracks</a>, together with Moa Johansson at the Department of Computer Science and Engineering.<br />&quot;We have got 22 applicants who will work in groups of five on different challenges from the world of sports&quot;, concludes Dan Kuylenstierna.<br /><br />Text: Michael Nystås<br />Photo of Johan Högstrand and Lina Korsgren: Mattias Reck<br />Photo of Dan Kuylenstierna: Michael Nystås<br /><br /><strong>Contact:</strong><br />Dan Kuylenstierna, Associate Professor, Microwave Electronics Laboratory, Department of Microtechnology and Nanoscience – MC2, Chalmers University of Technology, <br /><br /><a href="">See the feature on SVT Sport</a> (in Swedish) &gt;&gt;&gt;<br /><br /><a href="">Read more about powermeters for cross-country skiing</a> &gt;&gt;&gt;Thu, 02 Jul 2020 10:00:00 +0200 platform for shaping the interaction between micromechanical motion and light<p><b>​Researchers from Chalmers University of Technology have developed a novel experimental platform for the field of cavity optomechanics. The findings are a crucial step towards increasing light-matter interactions further in order to access new possibilities in the field of quantum technology. The work also shows the ability to fabricate two mechanical resonators on top of each other with a gap smaller than one micrometer. &quot;This ability is an important ingredient for the next step of the project&quot;, says Witlef Wieczorek, head of the group at MC2.</b></p><div><span><span><img src="/SiteCollectionImages/Institutioner/MC2/News/figure_2_350x305.jpg" alt="Picture of device" class="chalmersPosition-FloatLeft" style="margin:5px" /></span></span>How can light interact with matter? A rather evident way is via the radiation pressure force. However, this force is tiny. Or, have you already been pushed back by a laser pointer hitting you? But when we consider much smaller systems in the micro- and nano world, this force becomes appreciable and can actually be used to manipulate tiny objects. The radiation pressure force can even be enhanced in so-called cavity optomechanical devices. These devices exploit the interaction between light and micro- or nanomechanical resonators to alter the dynamical properties of either of the two systems. </div> <div><br /></div> <div><br /></div> <div><br /></div> <div><span><em>The figure above shows a </em><span></span><span><em>scanning electron microscope image<br />of a fabricated device: a 100 nanometer thin slab of GaAs is <br />freely suspended and hold by four strings above a GaAs substrate. <br />The holes in the device are a photonic crystal pattern that yield <br />high optical reflectivity at telecom wavelengths. <br />Image: Sushanth Kini Manjeshwar</em><span style="display:inline-block"></span></span><span style="display:inline-block"></span></span></div> <div><br /></div> <div>&quot;Cavity optomechanical devices open the door to a world of possibilities such as studying quantum mechanical behavior on larger scales or as transducing microwave to optical photons, which could prove invaluable in superconducting-based quantum computing&quot;, says Witlef Wieczorek.</div> <div><br /></div> In Witlef Wieczorek’s research group, the cavity optomechanics project deals with increasing the light-matter interaction even further to access novel possibilities for the field of quantum technology. The present work reports a crucial step in this direction and presents a novel experimental platform based on specifically tailored AlGaAs heterostructures. <br /><br /><img src="/SiteCollectionImages/Institutioner/MC2/News/figure3_sushanth_350x305.jpg" alt="Picture of Sushanth Kini" class="chalmersPosition-FloatRight" style="margin:5px" />Sushanth Kini Manjeshwar (to the right), PhD student in the lab of Witlef Wieczorek at MC2 and the lead author of the article, fabricated high-reflectivity mechanical resonators in AlGaAs heterostructures in the world-class nanofabrication cleanroom at MC2. The raw material, an epitaxially grown heterostructure on a GaAs wafer, was supplied by the group of professor Shu Min Wang at the Photonics Laboratory at MC2. <br />&quot;We patterned the mechanical resonators with a so-called photonic crystal, which can alter the behavior of light. Here, the photonic crystal enables an increase of the optical reflectivity of the mechanical resonator, which is a crucial requirement for the project&quot;, explains Sushanth Kini Manjeshwar.<br />The design of the photonic crystal pattern was developed by the group of associate professor Philippe Tassin at the Department of Physics at Chalmers.<br /> <br />The work also shows the ability to fabricate two mechanical resonators on top of each other with a gap smaller than one micrometer. This ability is an important ingredient for the next step of the project, where the researchers plan to integrate the presented devices in a chip-based optomechanical cavity. Their grand goal is then to access the elusive regime of strong interaction between a single photon and a single phonon, which is indispensable for realizing novel hardware for the field of quantum technology.<br /><br />This is the first experimental work from the Wieczorek Lab at the Quantum Technology Laboratory at MC2, and it has been published as Editor’s Pick in the special topic on Hybrid Quantum Devices in the scientific journal Applied Physics Letters.<br /><br /><div>The research was driven by a newly established collaboration amongst researchers from Chalmers comprising the groups of Witlef Wieczorek and Shu Min Wang, both at MC2, and of Philippe Tassin at the <span>Department of Physics<span style="display:inline-block">.</span></span></div> <br /><div>The work was jointly supported by Chalmers Excellence Initiative Nano, the Swedish Research Council (VR), the European QuantERA project C’MON-QSENS! and the Wallenberg Centre for Quantum Technology (WACQT).</div> <br />Text: Witlef Wieczorek and Michael Nystås<br />Illustration: Alexander Ericson, Swirly Pop AB<br />Image of device: Sushanth Kini Manjeshwar<br />Photo of Sushanth Kini Manjeshwar: Michael Nystås<br /><br /><strong>Contact:</strong><strong> </strong><br />Witlef Wieczorek, Assistant Professor, Quantum Technology Laboratory, Department of Microtechnology and Nanoscience – MC2, Chalmers University of Technology, Sweden,, <a href=""><span>wiecz</span><span></span></a><br /><br /><strong>Read the article in Applied Physics Letters &gt;&gt;&gt;</strong><br /><a href="">Suspended photonic crystal membranes in AlGaAs heterostructures for integrated multi-element optomechanics</a><br />Tue, 30 Jun 2020 09:00:00 +0200 million to develop communication systems of the future<p><b>​Niklas Rorsman, research professor at the Microwave Electronics Laboratory at MC2, receives 10 MSEK in research grant from the Swedish Foundation for Strategic Research (SSF). Now, he has the opportunity to develop his cooperation with Taiwan.</b></p>&quot;We are very happy! You are always pleasantly surprised when applications are granted. This is especially true of SSF's calls where competition is always hard. In this call, there were many applicants, so the chance that our application would be welcomed so positively was relatively small&quot;, says Niklas Rorsman.<br /><br /><img src="/SiteCollectionImages/Institutioner/MC2/News/nrorsman_350x305.jpg" class="chalmersPosition-FloatRight" alt="Picture of Niklas Rorsman." style="margin:5px" />He is funded with SEK 10 million for the new project &quot;Advanced GaN Devices for mm and sub-mm-wave communication&quot;.<br />&quot;We will try to optimize GaN transistors to operate at very high frequencies with the goal of being able to deliver enough output for the communication systems of the future. In the project, we will develop new materials and explore new component concepts to achieve this goal. We will be very dependent on the clean room and our measuring laboratory to be able to try and evaluate new ideas&quot;, explains Niklas.<br /><br />SSF awards a total of SEK 60 million to strengthen research collaboration with Taiwan in various projects. It is a new venture that complements the cooperation that SSF already has with Japan and South Korea.<br />&quot;I look forward to the fruition of this massively expanded collaboration between Swedish and Taiwanese researchers, including benefits to interacting industry with market opportunities stemming from innovations and scientific advances made in the projects&quot;, says professor and SSF CEO Lars Hultman in a press release.<br /><br />For Niklas Rorsman's part, a golden opportunity now arises to extend his existing exchange with Taiwan, by means of personnel, materials and knowledge:<br />&quot;We have long had a relatively close relationship with a group at National Chiao Tung University (NCTU) in Taiwan. So far, it has resulted in some &quot;dual-degree&quot; dissertations and we have had several guest doctoral students, who have been at Chalmers for about a year and worked with us in our projects&quot;, says Niklas.<br /><br />The hope is that doctoral students and researchers will be able to periodically spend time as guest researchers in Taiwan.<br />&quot;Taiwan is an interesting country to work with. They are one of the world's largest exporters of semiconductor technology&quot;, says Niklas.<br /><br />He describes himself as a country guy and a research professor who is most comfortable with lab work.<br />&quot;I am not so fond of air travel, but it might be necessary to travel to Taiwan now...&quot;<br /><br />Niklas Rorsman is one of only two Chalmers researchers to get support in this call, which received a total of 49 applications, of which six were granted. His happy colleague is Marianna Ivashina, professor at the Department of Electrical Engineering. She receives 10 million SEK for her project &quot;Antenna Technologies for Beyond-5G Wireless Communication&quot;.<br /><br />Text: Michael Nystås<br />Photo: Anna-Lena Lundqvist<br /><br /><div><a href="">Read press release from SSF</a> &gt;&gt;&gt;</div> <div><br /></div> <div><a href="/en/departments/e2/news/Pages/10-million-grant-to-antenna-research.aspx">Read more about Marianna Ivashina's grant</a> &gt;&gt;&gt;<br /></div>Thu, 25 Jun 2020 09:00:00 +0200 postdoc chooses Chalmers<p><b>​Gerard Higgins, postdoc at Stockholm University, has been awarded a prestigious International Postdoc Grant from the Swedish Research Council (VR) of 3 150 000 SEK. He will spend one year in the group of assistant professor Witlef Wieczorek at the Quantum Technology Laboratory at MC2 and two years in the groups of Prof. Markus Aspelmeyer and Dr. Michael Trupke at the University of Vienna, Austria. &quot;I want to learn from their experience&quot;, says Gerard.</b></p><img src="/SiteCollectionImages/Institutioner/MC2/News/ghiggins_private_350x305.jpg" class="chalmersPosition-FloatLeft" alt="Picture of Mr Higgins." style="margin:5px" />Gerard Higgins (to the left) is currently a member of Markus Hennrich's renowned research group at Stockholm University and will add much competence to Chalmers as soon as he gets here. <br /><br />Gerard gets his grant for a project aiming to develop a new experimental platform to test the validity of quantum mechanics on macroscopic scales:<br />“Quantum physics describes tiny particles like atoms and molecules extremely well, but it's unclear what causes the boundary from the miniscule quantum world to our classical macroscopic world, and there's no consensus on how we can unite quantum theory and general relativity. In this project I want to develop a new system that may provide insight into these questions”, says Gerard.<br /><br />He will spend two years in Markus Aspelmeyer's and Michael Trupke’s groups at the University of Vienna.<br />“Witlef's group at Chalmers and the teams around Markus Aspelmeyer and Michael Trupke at the University of Vienna have already been developing this kind of a system. I want to learn from their experience, and I want to push this promising research avenue forward. The Chalmers team and the Vienna teams are very welcoming, and the excellent clean room facilities at Chalmers are critical for the project's success”, says Gerard.<br /><br />The experimental platform consists of superconducting microparticles which are levitated using magnetic fields.<br />“The plan is to carefully control the microparticles, and to try to put them in a quantum superposition of two different locations. This would test whether quantum physics is obeyed in heavy systems, which are a billion times heavier than the largest molecules ever used for tests of quantum physics. This would open up the door for future work testing the gravitational field produced by a heavy particle that is in a quantum superposition of locations!”<br /><br />During his PhD and his first postdoc period, Gerard developed a new system that offers a promising new approach to quantum computing - so called trapped Rydberg ions. <br />“This involves exciting ions to gigantic Rydberg states, millions of times larger than normal atomic states. Ions in Rydberg states strongly interact with each other, and this enables faster quantum computing”, explains Gerard. <br /><br />Outside the lab, he enjoys exploring Stockholm's archipelago in his sailboat.<br />“Now, I'm looking forward to exploring the West coast/best coast!” concludes Gerard.<br /><br />The aim of the International Postdoc Grant is to offer researchers, who recently completed their PhDs at a Swedish Higher Education Institution, the opportunity to extend their networks and improve their qualifications through work stays abroad with secure employment conditions.<br /><br />The Swedish Research Council got a total of 155 applications in this call, of them only 38 received a yes. Only two Chalmers related scientists have been awarded this time. Apart from Gerard Higgins, a grant has been given to Kjell Jorner, a chemist who currently is a postdoctoral fellow at Astra Zeneca. <br /><br />The grant is awarded for the years 2020-2023.<br /><br />Text: Michael Nystås<br />Photo: Private<br /><br /><a href="">Read more about the decision</a> &gt;&gt;&gt;Wed, 17 Jun 2020 09:00:00 +0200 atom thin platinum makes a great chemical sensor<p><b>​Researchers at Chalmers University of Technology in Sweden, with collaborators, have reported the possibility to prepare one-atom thin platinum and use it as chemical sensors. The results were recently published in the scientific journal Advanced Material Interfaces.</b></p><div><img src="/SiteCollectionImages/Institutioner/MC2/News/Kyung_Kim_350x305.jpg" class="chalmersPosition-FloatRight" alt="Picture of Kyung Ho Kim." style="margin:5px" />“In a nutshell, we managed to make a one-atom thin metal layer, a sort of a new material. We found that this atomically-thin metal is super sensitive to its chemical environment: its electrical resistance changes significantly when it interacts with gases”, explains Kyung Ho Kim (to the right), postdoc at the Quantum Device Physics Laboratory at the Department of Microtechnology and Nanoscience – MC2, and lead author of the article. </div> <div> </div> <div>The spirit of the research is the development of 2D materials beyond graphene.  </div> <div>“Atomically thin platinum can be actually useful for ultra-sensitive and fast electrical detection of chemicals. We have studied the case of platinum in great detail, but other metals like Palladium produce similar results”, says Samuel Lara Avila (below to the right), Associate Professor at the Quantum Device Physics Laboratory at MC2, and one of the authors of the article.</div> <div> </div> <div><img src="/SiteCollectionImages/Institutioner/MC2/News/Samuel_Lara_Avila_1_350x305.jpg" class="chalmersPosition-FloatRight" alt="" style="margin:5px" />The researchers used the sensitive chemical-to-electrical transduction capability of atomically thin platinum to detect part-per-billion contents of toxic gases. They demonstrate this for detection of benzene, a compound that is cancerogenic to very small concentrations in ambient, and for which no low-cost detection apparatus exists. </div> <div>“This new material approach, atomically thin metals, is very promising for future air-quality monitoring applications”, says Jens Eriksson, Head of the Applied sensor science unit at Linköping University and co-author of the paper.</div> <div> </div> <div>The study is a collaboration between scientists from Chalmers, Linköping University, Uppsala University, University of Zaragoza (Spain), and the MAX IV Laboratory in Lund. From Chalmers, Kyung Ho Kim, Hans He and Sergey Kubatkin contributed to the research together with Samuel Lara-Avila.</div> <div> </div> <div>The work was jointly supported by the Swedish Foundation for Strategic Research (SSF), the Knut and Alice Wallenberg Foundation, The Swedish Research Council and Chalmers Excellence Initiative Nano. The experiments were performed in part at the Nanofabrication Laboratory at Chalmers.</div> <div> </div> <div>Text: Michael Nystås</div> <div>Illustration: Hans He</div> <div>Photo of Samuel Lara Avila: Jan-Olof Yxell</div> <div>Photo of Kyung Ho Kim: Private</div> <div> </div> <h3 class="chalmersElement-H3">Contact:</h3> <div>Samuel Lara Avila, Assistant Professor, Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience – MC2, Chalmers University of Technology, </div> <div> </div> <h3 class="chalmersElement-H3">Read the article in Advanced Material Interfaces &gt;&gt;&gt;</h3> <div>Chemical Sensing with Atomically Thin Platinum Templated by a 2D Insulator</div> <div><a href=""> </a></div> <div> </div> <h3 class="chalmersElement-H3">MORE ABOUT THE RESEARCH &gt;&gt;&gt;</h3> <div>Boosting the sensitivity of solid‐state gas sensors by incorporating nanostructured materials as the active sensing element can be complicated by interfacial effects. Interfaces at nanoparticles, grains, or contacts may result in nonlinear current–voltage response, high electrical resistance, and ultimately, electric noise that limits the sensor read‐out. </div> <div> </div> <div>This work reports the possibility to prepare nominally one atom thin, electrically continuous platinum layers by physical vapor deposition on the carbon zero layer (also known as the buffer layer) grown epitaxially on silicon carbide. With a 3–4 Å thin Pt layer, the electrical conductivity of the metal is strongly modulated when interacting with chemical analytes, due to charges being transferred to/from Pt. The strong interaction with chemical species, together with the scalability of the material, enables the fabrication of chemiresistor devices for electrical read‐out of chemical species with sub part‐per‐billion (ppb) detection limits. The 2D system formed by atomically thin Pt on the carbon zero layer on SiC opens up a route for resilient and high sensitivity chemical detection and can be the path for designing new heterogenous catalysts with superior activity and selectivity.</div>Mon, 15 Jun 2020 03:00:00 +0200 million grant to antenna research<p><b>​Marianna Ivashina receives a major grant from the Swedish Foundation for Strategic Research, to be used in a Swedish-Taiwanese collaborative research project to develop antenna technologies for the beyond-5G wireless communication applications, products, and services. ​</b></p>​<span style="background-color:initial">Professor Marianna Ivashina is leading the Antenna systems research group at the Department of Electrical Engineering at Chalmers University of Technology. Over the years, she has gathered extensive experience and knowledge in the design of array antennas for future wireless communication and sensor systems. During the next five years, she will be the leader of the project ‘Antenna Technologies for Beyond-5G Wireless Communication’. </span><div><br /></div> <div>This is one out of six projects granted in the announcement from the Swedish Foundation for Strategic Research (SSF) to strengthen the Swedish-Taiwanese research collaboration.</div> <div><br /></div> <div>“Our work will be based on existing and newly established collaborations between five academic groups in Sweden and Taiwan”, says Marianna Ivashina. </div> <div><br /></div> <div><strong>Antenna solutions for future wireless communication </strong></div> <div>“We aim to develop robust, energy-efficient, and highly-compact antenna array solutions for frequencies exceeding 100 GHz, as future enabling technologies for beyond-5G (B5G) applications, products, and services.”</div> <div><br /></div> <div>The main objective of the project is to investigate innovative antenna array architectures to solve the major challenges of physical and manufacturing complexities at millimeter-wave frequencies. To maximise energy efficiency, new circuit design concepts for non-conventional antenna functionalities will be developed. Additionally, advanced Silicon-micromachining will be applied to enable technology using highly compact antenna arrays.</div> <div><br /></div> <div>The project is supported and guided by several industrial partners, including small and medium-sized businesses, as well as one of the world’s largest telecom system providers. Among the collaborating partners are Ericsson, Gapwaves, Gotmic, Cyntec (Delta Electronics Group), and Powertech Technology.</div> <div><br /></div> <div>“I believe that this academic-industrial collaboration is an important factor for success to optimise the impact and utilisation of the technologies that we will develop”, says Marianna Ivashina. “Also, this is an excellent opportunity for our industrial partners to learn about the possibilities and limitations of emerging antenna technologies.”</div> <div><br /></div> <div><strong>Two out of six Swedish-Taiwanese projects from Chalmers</strong></div> <div>SSF also grants another project originating from Chalmers: “Advanced GaN Devices for mm and sub-mm-wave communication” led by Niklas Rorsman from the Department of Microtechnology and Nanoscience.</div> <div><br /></div> <div>The six projects are financed with SEK 10 million each over a five-year period.</div> <div><br /></div> <div>These research grants strengthen the foundation's investments in exchanges with democracies in East Asia regarding technology and science. SSF already has ongoing research collaborations with Japan and South Korea.</div> <div><br /></div> <div><div><a href="" target="_blank"><img class="ms-asset-icon ms-rtePosition-4" src="/_layouts/images/icgen.gif" alt="" />Read more about the Swedish-Taiwanese research collaboration on the web page of the Swedish Foundation for Strategic Research​</a></div> <div><br /></div></div>Fri, 12 Jun 2020 00:00:00 +0200 mechanical phase forms a crystal<p><b>​Researchers at Chalmers University of Technology in Sweden and Montana State University in the US have developed a theory that derives a so-called &quot;phase crystal&quot;, that elicits spontaneous magnetic fields and circulating currents. The theory predicts when a phase crystal can arise, explaining previous numerical results, and is presented in an article recently published in the scientific journal Physical Review Research.</b></p><div>Quantum mechanical states are described by a complex-valued wave function, which similar to a wave has both an amplitude and a phase. In contrast to a classical wave, the amplitude and phase of the wave function are related to purely quantum mechanical phenomena which lack an analogue in classical physics.</div> <div> </div> <div>“A perfect example is superconductivity, which is a quantum-mechanical state that arises in certain materials due to electron pairing. The pairs have a quantum-mechanical wave function with an amplitude corresponding to the pair density, and a phase which is related to the pair momentum. The pairs move like an inviscid fluid through the material, with zero electrical resistance”, explains Patric Holmvall (below to the left), researcher at the Applied Quantum Physics Laboratory at MC2, and the lead author of the article.</div> <div> </div> <div><img src="/SiteCollectionImages/Institutioner/MC2/News/pholmvall_350x305.jpg" alt="Picture of Patric Holmvall." class="chalmersPosition-FloatLeft" style="margin:5px" />The researchers’ study shows that in certain superconductors with pathological edges that destroy superconductivity, the kinetic energy can change sign and become favorable as it “heals” the destroyed superconductivity. </div> <div>“We find that the phase crystallizes and form a periodic pattern, which in turn creates a checker-board pattern of circulating currents and spontaneous magnetic fields”, says Patric Holmvall.</div> <div> </div> <div>Currents and magnetic fields usually only enter superconductors under external influence and perturbations, but now arise spontaneously. This is an example of spontaneous pattern-formation, where inhomogeneities which usually cost energy instead heal a destroyed system. </div> <div>“We have derived the conditions for phase crystallization and use a microscopic theory to show that these conditions are satisfied in for example the material YBCO. Our theory combines and explains a number of theoretical studies reaching all the way back to the 1990s, in particular our previous numerical results, which were recently published in Nature Physics and Nature Communications”, says Patric Holmvall.</div> <div> </div> <div>The researchers' studies show that phase crystals represent a unique class of inhomogeneous ground states. </div> <div>“To derive the conditions for phase crystallization, we had to generalize the commonly used Ginzburg-Landau theory, to take into account non-local interactions. Since this theory is used not just to study superconductivity, but also in, for instance, biological physics and liquid crystals, we think that new interesting phenomena might be discovered within these disciplines through a similar generalization”, says Patric Holmvall.</div> <div> </div> <div>The new study has several connections to previous research at Chalmers. Patric Holmvall gives examples of the beautiful patterns found in liquid crystals, the organization of cells and bacteria in thin films, or structural coloration and iridescence in plants and animals, the latter caused by so-called photonic structures. These exemplify how surface interactions can trigger spontaneous pattern formation.</div> <div> </div> <div>In addition to Patric Holmvall, the Chalmers professors Mikael Fogelström and Tomas Löfwander, as well as Anton Vorontsov at Montana State University in the US, have co-authored the article “Phase crystals”. It was highlighted as Editor's Suggestion, where extra interesting and well-written articles are selected.</div> <div> </div> <div>Text: Michael Nystås</div> <div>Illustration: Patric Holmvall</div> <div>Photo of Patric Holmvall: Kevin Marc Seja</div> <div> </div> <div><strong>Contact:</strong></div> <div>Patric Holmvall, Applied Quantum Physics Laboratory, Department of Microtechnology and Nanoscience – MC2, Chalmers University of Technology, </div> <div> </div> <div><a href="">Read the article in Physical Review Research</a> &gt;&gt;&gt;</div> <div> </div> <h3 class="chalmersElement-H3">FACTS ABOUT PHASE CRYSTALS</h3> <div>Phase crystals differ from other inhomogeneous superconducting states (e.g. Abrikosov-vortices and the Fulde-Ferell-Larkin-Ovchinnikov state), as they appear mainly at low temperatures even in the absence of external magnetic fields. Furthermore, an analysis of the free energy shows that it is mainly the phase rather than the amplitude which drives and characterizes the phase transition, in contrast to the traditional picture in superconductivity.</div> <div> </div> <h3 class="chalmersElement-H3">FACTS ABOUT SUPERCONDUCTORS</h3> <div>The superconducting ground state is characterized by the pair wave function, with an amplitude proportional to the pair density, and where variations in the phase are proportional to both the pair momentum and the electromagnetic potential. For a given system, the wave function assumes the amplitude and phase with the lowest free energy. Since pairs with a finite momentum (i.e. finite variations in the phase) lead to a kinetic energy, the ground state normally assumes a uniform phase without variations. The ground state is thereby mainly characterized by the amplitude and has zero kinetic energy.</div> <div> </div> <h3 class="chalmersElement-H3">RELATED CHALMERS RESEARCH</h3> <div><strong>Associate Professor Per Rudquist's Liquid Crystals Research:</strong></div> <div><a href=""></a> </div> <div> </div> <div><strong>Photonic Structures - research at the Photonics Laboratory, among others:</strong></div> <div><a href=";query=photonic+structures">;query=photonic+structures </a></div> <div> </div> <div><strong>The conditions for the formation of phase crystals are fulfilled in, for example, superconductors of the material YBCO:</strong></div> <div> </div> <div>Gustafsson, D., Golubev, D., Fogelström, M. et al. Fully gapped superconductivity in a nanometre-size YBa2Cu3O7–δ island enhanced by a magnetic field. Nature Nanotech 8, 25–30 (2013). <br /><a href=""> </a></div> <div> </div> <div><strong>The theory combines and explains a number of theoretical studies since the 1990s, especially previous numerical results:</strong></div> <strong> </strong><div><strong> </strong></div> <strong> </strong><div><strong>High temperature superconductors can fulfill the hairy ball theorem</strong></div> <div>The hairy ball theorem in mathematics says that one cannot comb a hairy ball smoothly without forming a vortex. One consequence of this is that there must always be at least one cyclone somewhere on earth. In 2018, researchers at Chalmers conducted a theoretical study of high-temperature superconductors and concluded that there is a low-temperature phase at the edges of the material described by an order parameter, a two-dimensional vector field, which must also fulfill a variant of the hairy ball theorem.</div> <div> </div> <div>Holmvall, P., Vorontsov, A.B., Fogelström, M., and Löfwander, T., Broken translational symmetry at edges of high-temperature superconductors, Nature Communications 9, 2190 (2018).</div> <div><a href=""></a> </div> <div> </div> <div><strong>A necklace of fractional vortices</strong></div> <div>Researchers at Chalmers have arrived at how what is known as time-reversal symmetry can break in a class of superconducting materials. Small circulating currents and magnetic fields are created at their edges. Adjacent circulating currents have opposite circulation, which generates magnetic fields of opposite sign. This effect causes the material to appear to have been dressed with a necklace of small magnetic fluxes.</div> <div><a href="/en/departments/mc2/news/Pages/A-necklace-of-fractional-vortices.aspx"> </a></div> <div> </div> <div>Håkansson, M., Löfwander, T. and Fogelström, M. (2015) Spontaneously broken time-reversal symmetry in high-temperature superconductors, Nature Physics (1745-2473), Vol. 11 (2015), 9, pp. 755-760.</div> <div><a href=""></a></div>Fri, 08 May 2020 09:00:00 +0200 online thesis defence went smoothly<p><b>​Andreas Bengtsson, PhD student at the Quantum Technology Laboratory, successfully defended his doctoral thesis on 24 April. It was the second defence arranged online at MC2 this spring.</b></p><div><img src="/SiteCollectionImages/Institutioner/MC2/News/andreas_bengtsson_350x305.jpg" class="chalmersPosition-FloatRight" alt="Picture of Andreas Bengtsson." style="margin:5px" />Due to the virus outbreak, Andreas Bengtsson (to the right) had to defend his thesis &quot;Quantum information processing with tunable and low-loss superconducting circuits&quot; via the video conferencing system Zoom and in front of a very small audience in the lecture hall Kollektorn.</div> <div> </div> <div>We asked Andreas to summarize his experiences from the special day:</div> <div>&quot;Overall, I think it went well. The big disadvantage of defending online is that it is more difficult to interpret the body language of those who ask questions, which probably made my answers more drawn out. I probably wasn't as nervous as I think I would have been if it had been a hall full of people. Then of course it was sad to not be able to celebrate with loved ones after the defence&quot;, he says.</div> <div> </div> <div>The grading committee and the opponent, Dr. Hanhee Paik from IBM TJ Watson Research Center, USA, also participated via Zoom. Chairperson of the day was MC2 professor Åsa Haglund.</div> <div>&quot;Although I had obviously preferred a normal dissertation, I appreciated that it was broadcasted online so that friends and colleagues from other countries could follow it. So I strongly recommend to continue with live broadcasts in the future, but with the opponent, the grading committee and other interested parties present at Chalmers&quot;, says Andreas.</div> <div> </div> <h3 class="chalmersElement-H3">What is your thesis about?</h3> <div>&quot;I have worked with several topics, all related to quantum computing. First of all, I developed and qualified the fabrication processes in the cleanroom that we use to build superconducting circuits with low loss. It was a lot of work in the cleanroom and to build the measurement setup&quot;, Andreas explains.</div> <div> </div> <div>He continues:</div> <div>&quot;Then, I used these circuits to implement two quantum algorithms. Right now, the quantum computer is too small to do anything that a normal computer cannot. However, we showed that one of our algorithms can be used to solve certain problems with applications in, for instance, logistics. Hopefully we can now scale up the size of the quantum computer and tackle problems that a normal computer cannot solve.&quot;</div> <div> </div> <div>Andreas future plans is to continue his work abroad:</div> <div>&quot;Due to the current covid-19 situation, the job search has gone slower than normal. But the plan is to work on developing quantum computers, albeit in a more industrial role, in the United States. Until the borders open up, I continue as a postdoc researcher here at Chalmers&quot;, he says.</div> <div> </div> <div>Ulf Andersson, IT-coordinator, kept an eye on the technology, while Linda Brånell, administrator, watched over the Zoom system.</div> <div>&quot;I really want to thank them both for their efforts. The technology worked completely flawless&quot;, says Andreas.</div> <div> </div> <div>Text: Michael Nystås</div> <div>Photo: Private</div> <div> </div> <div><a href="">Read Andreas Bengtsson's doctoral thesis</a> &gt;&gt;&gt;</div>Thu, 07 May 2020 11:00:00 +0200 made her way to space<p><b>​As a child, she never dreamed of working on space exploration, but the goal was always to study at Chalmers. Following her studies in Engineering Physics and her PhD at MC2, Sofia Rahiminejad got a top job at NASA&#39;s Jet Propulsion Laboratory in California, USA. &quot;Now that I&#39;m there, I think everything that has to do with space is super cool&quot;, she says.</b></p><h3 class="chalmersElement-H3">Why did you choose Engineering Physics at Chalmers?</h3> <div>&quot;I had read that it was the least practical education of all and thought “What a great thing! Then nothing can go wrong.” I had joined the Electrical Program at the upper secondary school which was a very practical education where things always broke down. I had it easy for math when I was younger and physics was really an extension of math for me. But the program turned out to be much more demanding than I thought. My trick was to always write my own summaries after reading the texts in the books, so that I actually understood what it was that we learned.&quot;</div> <div> </div> <h3 class="chalmersElement-H3">How would you describe your student life?</h3> <div><img src="/SiteCollectionImages/Institutioner/MC2/News/Sofia_bild2.jpg" alt="Picture of Sofia Rahiminejad." class="chalmersPosition-FloatRight" style="margin:5px" />&quot;It was almost more hectic than the studies because I wanted to be part of everything, but for me it was also a prerequisite for being able to do the studies. I was in the F-Spexet where I learned to be a good speaker. I have great use for that now when I give presentations. I was also in a public relations association at Chalmers and it was a lot of fun, but also a lot of effort. There I learned how to organize my time in a good way.&quot;</div> <div> </div> <h3 class="chalmersElement-H3">What are you working on at Nasa?</h3> <div>&quot;We want to find water and life on other planets. Often, water is an indication of life, but also a sign that we may be able to visit other planets and settle there in the future. One method used to look for these things is to send out spacecrafts that look at other planets, moons and asteroids with radar. When you do this today, the entire vehicle has to move in order to map a surface. It runs slowly and requires a lot of energy. My work is to try to streamline the process of phase shifters controlled by micromotors, which in turn can be used to design electrically controllable antennas that do not need to move when mapping a surface.&quot;</div> <div> </div> <h3 class="chalmersElement-H3">What was the best thing you got from your education?</h3> <div>&quot;Learning to learn, the ability to get into a subject or process quickly and having methods to do it. I am also happy for all the friends I made for life. We are a great gang of girls from Engineering Physics who all chose to work with very different things and we meet as often as we can!&quot;</div> <div> </div> <div>Text: Vedrana Sivac</div> <div>Photo: Private</div> <div><br /></div> <div>Footnote: After graduating with a degree in engineering physics, Sofia Rahiminejad began a research career in the Electronics Materials and Systems Laboratory at the Department of Microtechnology and Nanoscience - MC2, Chalmers. She completed her PhD in December 2016. She continued as a postdoctoral fellow at NASA's Jet Propulsion Laboratory (JPL) in 2017, with the help of the Wenner-Gren foundation fellowship award, as well as additional funding from the Barbro Osher Pro Suecia Foundation. </div>Mon, 20 Apr 2020 09:00:00 +0200 head of the Microwave Electronics Laboratory<p><b>​Professor Christian Fager is new head of the Microwave Electronics Laboratory (MEL) at MC2 from 1 April. &quot;It will be very exciting and important to continue develop the microwave research at Chalmers, together with all the staff at MEL&quot;, he says.</b></p><img src="/SiteCollectionImages/Institutioner/MC2/News/christian_fager_IMG_7373_350x305.jpg" class="chalmersPosition-FloatRight" alt="Picture of Christian Fager." style="margin:5px" />Christian Fager, to the right, is succeeding professor Herbert Zirath, who has been head ever since the beginning in 2001. Now, he's looking forward to continue and further develop Zirath's work.<br />&quot;Like Herbert, I am very passionate about our collaborations with industry. I find it a great satisfaction to see how our research benefits, both through the people we educate, but also in the added value created when we work to find new and better solutions to relevant challenges&quot;, says Christian.<br /><br />He doesn't think there are any lack of relevant challenges:<br />&quot;The number of wireless applications is increasing all the time. This is where our unique breadth comes in - our research actually ranges from semiconductor material to the whole radio system.&quot;<br /><br />Christian Fager has over the years profiled himself as a successful researcher with focus on investigating and developing new types of radio transmitters for mobile communication. He has received a number of awards. To mention a few, as recent as 2019 he got a scholarship from the donor fund Barbro Osher Endowment, which supports Chalmers researchers' visits at US universities. It gave him the opportunity to spend two weeks as a visiting researcher at Georgia Institute of Technology in Atlanta, USA. In 2018 he was appointed ​Chalmers Research Supervisor of the Year, and in 2010 he got the Areas of Advance Award.<br /><br />Herbert Zirath remains as manager of one of the two units at MEL. Fager will act as both unit manager and head of laboratory.<br /><br />Text and photo: Michael NyståsThu, 02 Apr 2020 09:00:00 +0200