”It feels incredible – I’m really amazed.
The prize is a recognition of almost everything I have done during my career as
a researcher,” says Anne L’Huillier, professor in atomic physics at Lund
University.
She shares the 2022 Wolf Prize in Physics
with professors Paul Corkum at the University of Ottawa, Canada, and Ferenc
Krausz at the Max Planck Institute for Quantum Optics in Germany.
“I have collaborated with many researchers,
but very little with Corkum and Krausz. Having entered the field from different
directions, we have mostly done complementary work. My entrance, and somewhat
my privilege, is that I have been involved from the very beginning,” she says.
It all started in 1988, when Anne
L’Huillier and her colleagues in Paris discovered high-order harmonics of light
being generated in a gas exposed to an intense laser field.
“It was a bit of a coincidence. Our
intention was to study fluorescence in the gas, but instead we saw these
high-order harmonics. I found it very fascinating and really got stuck in
exploring this new phenomenon which is an interesting combination of atomic
physics, more precisely the response of an atom to a strong laser field and
non-linear optics.”
A powerful titanium sapphire laser – the
first of its kind in Europe – brought Anne L’Huillier to Lund in 1992 to do
experiments. Two years later, she moved to Lund permanently to share her life
with one of the researchers behind the Lund high-power laser facility.
Early on, it was theoretically predicted that
if the high-order harmonics can be synchronized with each other, it would
result in a series of extremely short light pulses, with durations of a few
tens or hundreds of attoseconds. It took the field 14 years, until 2001, to show
it experimentally.
The time scale is unfathomably short; an
attosecond is no more than a billionth of a billionth of a second. Using light
pulses this short as “camera flashes” enables the detection of the incredibly
rapid motion of electrons.
“The second part of my research has been to
use these pulses to study the ultrafast dynamics of atoms and molecules,
especially photoionization,” tells L’Huillier.
In their experiments with the short pulses,
her team constantly creates entangled quantum states – entangled electron pairs,
entangled ion and electron, and entangled degrees of freedom. During the last
couple of years, L’Huillier – and part of the research field – have become
increasingly interested in characterising these entangled quantum states, and
understanding their decoherence mechanism (the concepts of entangled states and
decoherence are explained in the WACQT website).
In 2021, L’Huillier became one of the
principal investigators in the WACQT management, where she is one of the
coordinators of research in quantum sensing. She also leads a WACQT project on characterizing
and controlling atomic matter on attosecond timescales.
“Anne L’Huillier’s group brings important
expertise to WACQT regarding time-resolved spectroscopy and control of the
dynamics of quantum systems,” says Göran Wendin, senior advisor in WACQT and also
theoretical supervisor of L’Huillier when she was a PhD student in Paris and during
her postdoc at Chalmers in 1986.
“Being a part of WACQT is really exciting.
I learn new things and follow the development of the quantum information field.
We want to apply many of the concepts from this field to the entangled
electrons that we create with our attosecond pulses,” says Anne L’Huillier.
The work done within WACQT is one of her
main priorities at the moment. Another priority is to work with industrial
applications in order to contribute to the utilisation of attosecond light
pulses. The fact that these pulses are coherent and broadband is of interest,
for example, for the semi-conductor industry.
“I see a very nice future for ultrashort
laser pulses, with many applications in different directions. After 30 years
with titanium sapphire lasers, there is now a shift to ytterbium-based laser
systems which are much smaller and easier to handle. This should open the field
also to people who are not laser specialists, but rather specialists within one
of the many possible applications,” L’Huillier predicts.
About
the Wolf Prize
The Wolf Prize is awarded annually by the
Israeli Wolf Foundation to outstanding scientists and artists from around the
world for “achievements promoting science and art in the interest of mankind
and friendly relations among peoples, regardless of race, religion, gender,
geographical location or political opinion.”
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more
The Wolf Prize
Anne L’Huillier’s research group
Text: Ingela Roos