Credit: Waqar Khan 

New microwave photon detector can lead to better quantum computers

In a pioneering experiment, a research team in Lund has succeeded in constructing a new and very efficient microwave photon detector. The discovery could accelerate the development of quantum computers.


Microwave photons are commonly used in quantum technology, for example to manipulate and read out qubits in superconducting quantum computers.

“For communication between the parts of a quantum computer to be possible, you have to be able to detect individual microwave photons very efficiently,” says Peter Samuelsson, theoretical physicist at Lund University.

While there are many detectors available for optical photons, detectors for microwave photons are way more difficult to accomplish due to the much lower energy of microwave photons. But now, a team of WACQT researchers at Lund University, led by Ville Maisi and Peter Samuelsson, has succeeded in creating an efficient and continuous microwave photon detector, based on a semiconducting nanowire with a high-quality double quantum dot coupled to a cavity.

“This setup allows us to continuously detect microwave photons by converting them into a measurable flow of electrons. This means that the detector can be left on, it doesn’t need to know when the photon will arrive, which is often required in currently available detectors,” says Ville Maisi.

Now the team is working on further improving the efficiency of the detector – the goal is to be able to detect every individual microwave photon as a ‘click’.

The results have been published in Nature Communications. Also read more in a news article at the Lund University website.

Page manager Published: Fri 08 Oct 2021.