Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quality control of quantum simulators

18.11.2015

Scientists of the FU Berlin, the Universidade Federal do Rio de Janeiro, and the MPQ develop a new certification method for photonic quantum simulators.

In the past 20 years, the development of devices that exploit the laws of quantum physics has made impressive progress. New quantum technologies promise a variety of exciting applications, for example in the field of quantum information processing or for the safe encoding of data. Hence, the commercial use of quantum devices has now become feasible.


Graphic: image background: public domain / stamp: ICFO, Spain

There is, however, a severe obstacle to overcome: the lack of practical tools for certifying the functionality of the devices. This prevents the transformation of complex laboratory set-ups into commercial products. Now, an international team of scientists has proposed a new certification method that applies to photonic devices in which light quanta serve as the carriers of quantum information.

This new method, developed by Prof. Dr. Jens Eisert (Freie Universität Berlin), Prof. Dr. Leandro Aolita (Universidade Federal do Rio de Janeiro), Dr. Christian Gogolin, postdoctoral scientist in the Theory Division at MPQ (Garching) and Research Fellow at ICFO (Barcelona), as well as Martin Kliesch (Freie Universität Berlin), is characterized by its high reliability and simplicity (Nature Communications, 18th November 2015, DOI 10.1038/NCOMMS9498).

It is an important step towards exploiting the quantum mechanical behaviour of quantum many-body systems in a controlled way.

Quantum simulation as well as quantum cryptography has become increasingly important in the past years. The ultimate goal of all these efforts is a “general purpose computer”, a device with the power to solve all kinds of different problems, and outperforming any classical computer in terms of speed.

How to achieve this goal remains a question of active research at present. There is, however, a kind of intermediate stage that is now within reach: so-called quantum simulators. By making use of quantum effects, these devices can at least solve certain specific tasks that cannot be treated efficiently with classical methods. They are fast, but not universal.

Quantum optics represents a platform for the implementation of quantum simulators. Here the quantum mechanical properties of light quanta (so-called photons), such as entanglement and superposition, are being used. But how can one make sure that machines that rely on the use of microscopic particles work the way they are supposed to? “Certification is very difficult, in particular in case of non-universal quantum computers,” Dr. Christian Gogolin explains.

“This is, because quantum simulators are limited in their capability to perform calculations. So you cannot run any kind of certification program. Instead, the program has to be tailored according to the specific properties of the quantum simulator.”

The problem of certification can be understood in terms of a game in which one very powerful player – let’s call him Merlin – challenges a much less powerful opponent, let’s call him Arthur. Merlin claims to be in possession of a quantum simulator, but Arthur is doubtful.

He wants to have a proof that this is true, and that Merlin’s quantum simulator is indeed capable of solving problems that exceed his (Arthur’s) own abilities. The goal is to find a way for Arthur that allows him – despite of his limited resources – to check whether Merlin owns a functioning quantum simulator.

In their publication the scientists propose a test that offers this kind of certification for a variety of optical quantum simulators. For one, Arthur has to be able to detect and characterize single photons. Second, he has to use a classical computer in order to check Merlin’s solutions and make sure that his quantum simulator delivers the correct values. After a calculable number of “rounds” in this game Arthur will know with a certainty of say 99.9 % whether Merlin is able to prepare a selected quantum state to a selected precision.

The experimental techniques that are available today provide a surprisingly large number of potential applications of quantum effects. That makes it all the more important to prove that the methods live up to their claims. “Up to now, most of the effort went into the realization of quantum technologies whereas certification received hardly any attention”, Prof. Jens Eisert elaborates.

“Now we have reached a point where this bottleneck hinders further experimental progress. The method we propose is rather simple, yet very reliable. Though it is tailored for optical devices, it also contributes to finding a general solution for the problem of certification.” Olivia Meyer-Streng

Orginal publication:
Leandro Aolita, Christian Gogolin, Martin Kliesch, and Jens Eisert
Reliable quantum certification for photonic quantum technologies
Nature Communications, 18 November 2015, DOI 10.1038/NCOMMS9498

Contact:
Prof. Dr. J. Ignacio Cirac
Honorary Professor TU München and
Director at the Max Planck Institute of Quantum Optics
Hans-Kopfermann-Str. 1, 85748 Garching, Germany
Phone: +49 (0)89 32 905 -705/-736 / Fax: -336
E-mail: ignacio.cirac@mpq.mpg.de

Dr. Christian Gogolin
ICFO - The Institute of Photonic Sciences
Mediterranean Technology Park,
Av. Carl Friedrich Gauss, 3,
08860 Castelldefels (Barcelona), Spanien
Phone: +34 935 54 22 37
E-mail: christian.gogolin@icfo.es

Dr. Olivia Meyer-Streng
Press & Public Relations
Max Planck Institute of Quantum Optics, Garching, Germany
Phone: +49 (0)89 32 905 -213
E-mail: olivia.meyer-streng@mpq.mpg.de

Dr. Olivia Meyer-Streng | Max-Planck-Institut für Quantenoptik
Further information:
http://www.mpq.mpg.de/

More articles from Physics and Astronomy:

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

nachricht Mars 2020 mission to use smart methods to seek signs of past life
17.08.2017 | Goldschmidt Conference

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New gene catalog of ocean microbiome reveals surprises

18.08.2017 | Life Sciences

Astrophysicists explain the mysterious behavior of cosmic rays

18.08.2017 | Physics and Astronomy

AI implications: Engineer's model lays groundwork for machine-learning device

18.08.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>