Aalto University scientists have broken the world record by fourteen fold in the energy resolution of thermal photodetection.
The record was made using a partially superconducting microwave detector. The discovery may lead to ultrasensitive cameras and accessories for the emerging quantum computer.
This is an artistic image of a hybrid superconductor-metal microwave detector.
Credit: Ella Maru Sudio
The first of the two key enabling developments is the new detector 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 scientists used something called positive feedback. This means that there is an external energy source that amplifies the temperature change arising from the absorbed photons.
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.
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 energy levels or particles, and is in this sense more precise than classical thermodynamics", says Möttönen.
"There are also other groups developing single-photon microwave 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.
Full-resolution images: https:/
Images may be used free of charge in stories on this work.
Figure 1. Artistic image of a hybrid superconductor-metal microwave detector. Credit: Ella Maru Sudio.
Figure 2. Scanning-electron microscope image of the microwave detector. The nanowire is colored yellow and the other parts are superconducting aluminum. Photons arrive from the left and get absorbed at the long part of the nanowire. This leads to an elevated temperature and weakening of superconductivity at the short parts of the nanowire which consequently work as a sensitive thermometer. Credit: Joonas Govenius.
Research article: (This article should be credited as the source of stories covered.)
Joonas Govenius, Russell E. Lake, Kuan Yen Tan, and Mikko Möttönen,
" Detection of zeptojoule microwave pulses using electrothermal feedback in proximity-induced Josephson junctions ",
Physical Review Letters 117 (2016).
Article will be published on July 8th 2016: http://journals.
Free link to the non-copyedited article: http://arxiv.
For more information:
Mikko Möttönen, Docent
Department of Applied Physics
Joonas Govenius, M.Sc.
Department of Applied Physics
mobile: +358 50 435 3975
Mikko Möttönen | EurekAlert!
Did you know that the wrapping of Easter eggs benefits from specialty light sources?
13.04.2017 | Heraeus Noblelight GmbH
To e-, or not to e-, the question for the exotic 'Si-III' phase of silicon
05.04.2017 | Carnegie Institution for Science
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences