Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Developing reliable quantum computers

22.02.2018

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to ensure it is working reliably? Depending on the algorithmic task, this could be an easy or a very difficult certification problem.


Illustration: Quantum Optics and Statistics, University of Freiburg

An international team of researchers has taken an important step towards solving a difficult variation of this problem, using a statistical approach developed at the University of Freiburg. The results of their study are published in the latest edition of Nature Photonics.

Their example of a difficult certification problem is sorting a defined number of photons after they have gone through a defined arrangement of several optical elements. The arrangement provides each photon with a number of transmission paths - depending on whether the photon is reflected or transmitted by an optical element.

The task is to predict the probability of photons leaving the arrangement at defined points, for a given positioning of the photons at the entrance to the arrangement. With increasing size of the optical arrangement and increasing numbers of photons sent on their way, the number of possible paths and distributions of the photons at the end rises steeply as a result of the uncertainty principle which underlies quantum mechanics - so that there can be no prediction of the exact probability using the computers available to us today.

Physical principles say that different types of particle - such as photons or electrons - should yield differing probability distributions. But how can scientists tell these distributions and differing optical arrangements apart when there is no way of making exact calculations?

An approach developed in Freiburg by researchers from Rome, Milan; Redmond, USA; Paris, and Freiburg now makes it possible for the first time to identify characteristic statistical signatures across unmeasurable probability distributions. Instead of a complete “fingerprint,” they were able to distill the information from data sets which were reduced to make them usable.

Using that information, they were able to discriminate various particle types and distinctive features of optical arrangements. The team also showed that this distillation process can be improved, drawing upon established techniques of machine learning, whereby physics provides the key information on which data set should be used to seek the relevant patterns. And because this approach becomes more accurate for bigger numbers of particles, the researchers hope that their findings take us a key step closer to solving the certification problem.

Publication:
• Taira Giordani, Fulvio Flamini, Matteo Pompili, Niko Viggianiello, Nicolò Spagnolo, Andrea Crespi, Roberto Osellame, Nathan Wiebe, Mattia Walschaers, Andreas Buchleitner and Fabio Sciarrino (2018): Experimental statistical signature of many-body quantum interference. In: Nature Photonics. doi: 10.1038/s41566-018-0097-4

Further information:
• Mattia Walschaers (2016): Efficient quantum transport. Thesis, University of Freiburg and Springer Theses, upcoming (Springer Thesis Award 2017).
• Mattia Walschaers, Jack Kuipers, Juan-Diego Urbina, Klaus Mayer, Malte Christopher Tichy, Klaus Richter and Andreas Buchleitner (2016): Statistical benchmark for BosonSampling. In: New Journal of Physics 18.
• Mattia Walschaers, Frank Schlawin, Thomas Wellens and Andreas Buchleitner (2016): Quantum transport on disordered and noisy networks: an interplay of structural complexity and uncertainty. In: Annual Review of Condensed Matter Physics 7, S. 223–248.

Contact:
Prof. Dr. Andreas Buchleitner
Institute of Physics
University of Freiburg
Phone: 0761/203-5830
E-Mail: abu@uni-freiburg.de

Weitere Informationen:

https://www.pr.uni-freiburg.de/pm-en/press-releases-2018/developing-reliable-qua...

Rudolf-Werner Dreier | idw - Informationsdienst Wissenschaft

More articles from Information Technology:

nachricht Touchscreens go 3D with buttons that pulsate and vibrate under your fingertips
14.03.2019 | Universität des Saarlandes

nachricht EU project CALADAN set to reduce manufacturing cost of Terabit/s capable optical transceivers
11.03.2019 | IHP - Leibniz-Institut für innovative Mikroelektronik

All articles from Information Technology >>>

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 >>>