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 NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>