Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First quantum photonic circuit with electrically driven light source

27.09.2016

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast calculations involving enormous quantities of data or so-called quantum simulation, which allows highly complex systems to be reproduced on the computer.


Graphic representation of part of a chip, showing with photon source, detector and waveguides

Illustration: Münster University/Wolfram Pernice

So far, experiments researching into the applicability of this technology have filled entire laboratory rooms. In order to use this technology in a meaningful way, however, it needs to be accommodated in a very small space. For the first time researchers have now succeeded in putting a complete quantum optical set-up on a chip. This meets one requirement for making it possible to use photonic circuits for quantum computers.

The results have been published in the current issue of the “Nature Photonics” journal (advance online publication). Those involved in the study included a team of scientists from Germany, Poland and Russia – headed by Professors Wolfram Pernice from Münster University and Manfred Kappes and Carsten Rockstuhl from the Karlsruhe Institute of Technology (KIT).

The light source which the researchers used for the first time for the quantum photonic circuit was special nanotubes made of carbon. These have a diameter which is a hundred thousand times smaller than a human hair and they emit single light particles (photons) when stimulated by means of laser light. These photons are also known as light quanta, which explains the term “quantum photonic”.

The fact that the carbon tubes emit single photons makes them attractive as an ultra-compact light source for optical quantum computers. “However, the laser technology can’t be put onto a scalable chip just like that,” says physicist Wolfram Pernice, sounding a cautionary note. The scalability of a system – in other words, the possibility of miniaturizing components in order to increase the quantity – is, however, the precondition for using the technology for high-performance computers, all the way up to optical quantum computers.

Because all the elements on the chip now developed are driven electrically, no additional laser systems are necessary any more – which is a considerable simplification compared with conventional optical stimulation. “The development of a scalable chip which combines single photon source, detector and waveguides is an important step for researchers,” says Ralph Krupke, who is himself engaged in research at the KIT’s Institute of Nanotechnology and at the Institute of Material Science at the Technical University of Darmstadt. “As we were able to demonstrate that single photons can also be emitted by electrical stimulation of the carbon nanotubes, it means that we have overcome a limiting factor that was until now a barrier to any applicability.”

Turning to the methodology: the scientists looked to see whether single photons were emitted when electricity flowed through carbon nanotubes. For this purpose they used carbon nanotubes as single photon sources, superconducting nanowires as detectors and nanophotonic waveguides. One single photon source and two detectors were each connected to one waveguide. The set-up was cooled using liquid helium in order to be able to count individual photons. The chips were produced with an electron beam plotter.

The work done by the scientists is basic research. It is not yet clear whether – and, if so, when – it can be put into practice. Wolfram Pernice and lead author Svetlana Khasminskaya received funding from the German Research Foundation and the Helmholtz Association, while Ralph Krupke received financial support from the Volkswagen Foundation.

Original publication:

Khasminskaya S. et al. (2016): Fully integrated quantum photonic circuit with an electrically driven light source. Nature Photonics; DOI 10.1038/nphoton.2016.178

Media contact at KIT:

Kosta Schinarakis
Phone: +49 721 608 41956
Mail: schinarakis@kit.edu

Weitere Informationen:

http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2016.178.html Original publication ("Nature Photonics")

Dr. Christina Heimken | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-muenster.de/

More articles from Physics and Astronomy:

nachricht New manifestation of magnetic monopoles discovered
08.12.2017 | Institute of Science and Technology Austria

nachricht NASA's SuperTIGER balloon flies again to study heavy cosmic particles
07.12.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

Im Focus: A transistor of graphene nanoribbons

Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."

Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

Blockchain is becoming more important in the energy market

05.12.2017 | Event News

 
Latest News

Making fuel out of thick air

08.12.2017 | Life Sciences

Rules for superconductivity mirrored in 'excitonic insulator'

08.12.2017 | Information Technology

Smartphone case offers blood glucose monitoring on the go

08.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>