New record in microwave detection

July 8, 2016, Aalto University
New record in microwave detection
Credit: Aalto University

The record was made using a partially superconducting microwave detector. The discovery may lead to ultrasensitive cameras and accessories for the emerging quantum computer.

The first of the two key enabling developments is the new design consisting of tiny pieces of superconducting aluminum and a golden nanowire. This design guarantees both efficient absorption of incoming photons and very sensitive readout. The whole detector is smaller than a single human blood cell.

"For us size matters. The smaller the better. With smaller detectors, we get more signal and cheaper price in mass production", says Mikko Möttönen, the leader of the record-breaking Quantum Computing and Devices research group.

The new detector works at a hundredth of a degree above absolute zero temperature. Thermal disturbances at such low temperatures are so weak that the research team could detect energy packets of only a single zeptojoule. That is the energy needed to lift a red blood cell by just a single nanometer.

The second key development concerns the amplification of the signal arising from the tiny the energy packets. To this end, the researchers used something called positive feedback. This means that there is an external energy source that amplifies the temperature change arising from the absorbed photons.

Credit: Aalto University
From discovery to products

Microwaves are currently used in mobile phone communications and satellite televisions, thanks to their ability to pass through walls. More sensitive microwave detectors may lead to great improvements of the present communication systems and measurement techniques.

The European Research Council (ERC) has just awarded Möttönen a prestigious Proof of Concept Grant to develop the detector towards commercial applications. This was the third personal ERC grant awarded to Möttönen.

Besides communication systems the new detector could be used as a measurement device in the emerging superconducting quantum computer.

"Existing superconducting technology can produce single microwave photons. However, detection of such traveling photons efficiently is a major outstanding challenge. Our results provide a leap towards solving this problem using thermal detection," says Joonas Govenius who is the first author of the work.

New record in microwave detection
Artistic image of a hybrid superconductor-metal microwave detector. Credit: Ella Maru Studio
New Physics

A microwave detector may also be useful for thermodynamics of small systems, a new research area Möttönen has studied in collaboration with his Aalto colleague Professor Jukka Pekola.

Now Pekola and his group want to go to the quantum regime but they first need a detector capable of measuring the energy released by the quantum systems. This means that the detector should be able to accurately measure single microwave photons.

"Quantum thermodynamics may give yet another boost to technology since it deals with individual levels or particles, and is in this sense more precise than classical thermodynamics", says Möttönen.

"There are also other groups developing single-photon detectors such as that of Pekola. This is great since we can learn from each other and this way come up with even better products for future end users", concludes Möttönen.

Explore further: New invention revolutionizes heat transport

More information: Detection of zeptojoule microwave pulses using electrothermal feedback in proximity-induced Josephson junctions. journals.aps.org/prl/accepted/ … c584ce432d348e716602

Related Stories

New invention revolutionizes heat transport

February 1, 2016

Scientists at Aalto University, Finland, have made a breakthrough in physics. They succeeded in transporting heat maximally effectively ten thousand times further than ever before. The discovery may lead to a giant leap in ...

Hi-fi single photons

October 4, 2012

Many quantum technologies—such as cryptography, quantum computing and quantum networks—hinge on the use of single photons. While she was at the Kastler Brossel Laboratory (affiliated with the Pierre and Marie Curie University, ...

Breakthrough for photons in the microwave frequency range

February 22, 2011

Photons in the microwave frequency range are important in quantum research - for quantum information processors, for example. Now, for the first time, researchers have achieved the controlled production of single photons ...

Recommended for you

ATLAS experiment observes light scattering off light

March 20, 2019

Light-by-light scattering is a very rare phenomenon in which two photons interact, producing another pair of photons. This process was among the earliest predictions of quantum electrodynamics (QED), the quantum theory of ...

How heavy elements come about in the universe

March 19, 2019

Heavy elements are produced during stellar explosion or on the surfaces of neutron stars through the capture of hydrogen nuclei (protons). This occurs at extremely high temperatures, but at relatively low energies. An international ...

Trembling aspen leaves could save future Mars rovers

March 18, 2019

Researchers at the University of Warwick have been inspired by the unique movement of trembling aspen leaves, to devise an energy harvesting mechanism that could power weather sensors in hostile environments and could even ...

Quantum sensing method measures minuscule magnetic fields

March 15, 2019

A new way of measuring atomic-scale magnetic fields with great precision, not only up and down but sideways as well, has been developed by researchers at MIT. The new tool could be useful in applications as diverse as mapping ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.