Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How to certify a quantum computer

05.11.2018

SNSF-funded researchers have developed a protocol for checking that quantum computer components function as they should. That’s a critical step in making the promise of quantum computing – including unprecedented computing power – a reality.

Quantum computers are being developed by teams working not only at universities but also at Google, IBM, Microsoft and D-Wave, a start-up company. And things are evolving quickly, says Nicolas Sangouard, SNSF Professor at the University of Basel. “In a few years at most, I expect the computing power of quantum computers to significantly outstrip the computing power of ordinary computers. We call that ‘quantum supremacy’”.

Sangouard and his co-workers recently showed how to check that these computers are fit for purpose. For they are not just powerful but also very delicate: some operate at temperature extremes as low as 270 degrees below zero. The researchers’ approach enables them to certify all the components of a quantum computer – from short- and long-term memory, to information processors, to the converters required to connect the computer to a secure quantum communications network.

The protocol offers an additional advantage: it only uses the components already in the computer, thus obviating the need for additional devices. In principle, the protocol will work with any type of quantum computer, whatever the technology behind it.

A machine that tests itself

“The power of quantum computers is what makes them difficult to certify”, says Sangouard. “Even the fastest ordinary computers are too slow to check the calculations made by such devices.” Moreover, quantum computers will eventually be able to communicate with each other securely through a dedicated quantum communications network. So it’s important to make sure that they aren’t a weak link, says Sangouard.

That’s why the research team has developed a completely quantum certification method that uses the computer’s own building blocks. “We were inspired by Bell tests, which were devised by a physicist working at CERN in the 1960s”, says Sangouard. “Normally, these tests are used to check whether particles are behaving according to quantum rules. We modified the tests to enable them to check the operation of the various components of a quantum computer. Because such a device is basically capable of doing the tests, our procedure is very simple to set up and doesn’t require any special skills.”

“What prompted the project was a seminar talk by a scientist invited to the University of Basel”, says Sangouard. “The talk dealt with a complicated aspect of quantum physics, but we were motivated to translate it into a useful method for quantum computers. For me, that’s a perfect example of how a conference is not just a means of learning in a passive way but also offers significant opportunities to innovate.”

The research was carried out at the University of Basel during an SNSF Professorship – a scheme that has since been replaced by the SNSF Eccellenza Professorial Fellowships – and at the University of Innsbruck, thanks to a mobility grant. Nicolas Sangouard is an associate member of the National Centre of Competence in Research (NCCR) “QSIT – Quantum Science and Technology”, an SNSF funding scheme. He also takes part in the project Quantum Internet Alliance, part of the new FET Flagship programme “Quantum Technologies”.

Quantum computing

First proposed in the early 1980s, the concept of the quantum computer aims at exploiting the strange laws that govern the microscopic world to perform calculations that are impossible to do using ordinary computers. A quantum processor manipulates information and at the same time uses each quantum bit (“qubit”) to encode a continuum of numbers – not just the 1s and 0s encoded by ordinary digital bits. The pace of industrial development is accelerating: in November 2017, IBM announced that it had tested a 50-qubit computer.

Switzerland and Europe are on board

Switzerland is home to many world-class research groups working on quantum technologies. Most of them are participants in the National Centre of Competence in Research (NCCR) “QSIT – Quantum Science and Technology””, the goal of which is to develop technologies that exploit quantum physics, and in particular computers, communication protocols and quantum sensors. The NCCR is headed by Klaus Ensslin of ETH Zurich and co-directed by Richard Warburton at the University of Basel. In Europe, 20 projects have been selected on 28 October 2018 for the new FET Flagship «Quantum Technologies», which has a budget of one billion euro. Scientists from the universities of Basel, Geneva and Neuchâtel as well as from ETH Zurich and CSEM participate in the programme; two projects are coordinated by Swiss groups.

The text of this press release, a download image and further information are available on the website of the Swiss National Science Foundation:

Wissenschaftliche Ansprechpartner:

Prof. Nicolas Sangouard
Department of Physics
University of Basel
Klingelbergstrasse 82
CH-4056 Basel
Phone .: +41 61 207 39 15
E-mail: nicolas.sangouard@unibas.ch
https://qotg.physik.unibas.ch

Originalpublikation:

P. Sekatski, J.-D. Bancal, S. Wagner and N. Sangouard: Certifying the building blocks of quantum computers from Bell's theorem. Physical Review Letters (2018) doi:10.1103/PhysRevLett.121.180505 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.180505
https://arxiv.org/pdf/1802.02170.pdf

Weitere Informationen:

http://www.snf.ch/en/researchinFocus/newsroom/Pages/news-181105-press-release-ho...

Media - Abteilung Kommunikation | Schweizerischer Nationalfonds SNF

More articles from Physics and Astronomy:

nachricht Levitating objects with light
19.03.2019 | California Institute of Technology

nachricht Stellar cartography
19.03.2019 | Leibniz-Institut für Astrophysik Potsdam

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: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Molecular motors run in unison in a metal-organic framework

20.03.2019 | Life Sciences

Active substance from plant slows down aggressive eye cancer

20.03.2019 | Life Sciences

Novel sensor system improves reliability of high-temperature humidity measurements

20.03.2019 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>