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!
Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences
Researchers develop environmentally friendly soy air filter
16.01.2017 | Washington State University
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction