Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quantum Cloud Computing with Self-Check

16.05.2019

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists first simulated the spontaneous formation of a pair of elementary particles with a digital quantum computer at the University of Innsbruck.


A new method enables powerful quantum simulation on hardware available today

IQOQI Innsbruck/Harald Ritsch


from left: Rick van Bijnen, Christine Maier and Christian Kokail

IQOQI Innsbruck/M.R.Knabl

Due to the error rate, however, more complex simulations would require a large number of quantum bits that are not yet available in today's quantum computers. The analog simulation of quantum systems in a quantum computer also has narrow limits.

Using a new method, researchers around Christian Kokail, Christine Maier und Rick van Bijnen at the Institute of Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences have now surpassed these limits. They use a programmable ion trap quantum computer with 20 quantum bits as a quantum coprocessor, in which quantum mechanical calculations that reach the limits of classical computers are outsourced.

“We use the best features of both technologies," explains experimental physicist Christine Maier. “The quantum simulator takes over the computationally complex quantum problems and the classical computer solves the remaining tasks.”

Toolbox for Quantum Modelers

The scientists use the variational method known from theoretical physics, but apply it on their quantum experiment. „The advantage of this method lies in the fact that we can use the quantum simulator as a quantum resource that is independent of the problem under investigation,“ explains Rick van Bijnen.

„In this way we can simulate much more complex problems.“ A simple comparison shows the difference: an analog quantum simulator is like a doll's house, it represents reality. The programmable variational quantum simulator, on the other hand, offers individual building blocks with which many different houses can be built. In quantum simulators, these building blocks are entanglement gates and single spin rotations.

With a classical computer, this set of knobs is tuned until the intended quantum state is reached. For this the physicists have developed a sophisticated optimization algorithm that in about 100,000 requests of the quantum coprocessor by the classical computer leads to the result.

Coupled with extremely fast measurement cycles of the quantum experiment, the simulator at IQOQI Innsbruck becomes enormously powerful. For the first time, the physicists have simulated the spontaneous creation and destruction of pairs of elementary particles in a vacuum on 20 quantum bits.

Since the new method is very efficient, it can also be used on even larger quantum simulators. The Innsbruck researchers plan to build a quantum simulator with up to 50 ions in the near future. This opens up interesting perspectives for further investigations of solid-state models and high-energy physics problems.

Built-in Self-Check

A previously unsolved problem in complex quantum simulations is the verification of the simulation results. “Such calculations can hardly or not at all be checked using classical computers. So how do we check whether the quantum system delivers the right result,” asks the theoretical physicist Christian Kokail. “We have solved this question for the first time by making additional measurements in the quantum system. Based on the results, the quantum machine assesses the quality of the simulation,” explains Kokail.

Such a verification mechanism is the prerequisite for even more complex quantum simulations, because the necessary number of quantum bits increases sharply. “We can still test the simulation on 20 quantum bits on a classical computer, but with more complex simulations this is simply no longer possible,” says Rick van Bijnen. “In our study, the quantum experiment was even faster than the control simulation on the PC. In the end, we had to take it out of the race in order not to slow down the experiment,” says the physicist.

Innsbruck Quantum Cloud

This research achievement is based on the unique collaboration between experiment and theory at the Innsbruck quantum research center. The expertise from years of experimental quantum research meets innovative theoretical ideas in Tyrol, Austria. Together, this leads to results that are recognized worldwide and establishes an internationally leading position of Innsbruck's quantum research. "15 years of very hard work have gone into this experiment," emphasizes experimental physicist Rainer Blatt.

“It is very nice to see that this is now bearing such beautiful fruit.” The theoretical physicist Peter Zoller adds: “We in Innsbruck are not only leaders in the number of available quantum bits, but have now also advanced into the field of programmable quantum simulation and were able to demonstrate for the first time the self-verification of a quantum processor. With this new approach, we are bringing the simulation of everyday quantum problems within reach.”

The work now published in Nature was financially supported by the Austrian Science Fund FWF and the European Union, among others.

Wissenschaftliche Ansprechpartner:

Christine Maier
Institute of Quantum Optics and Quantum Information
Austrian Academy of Sciences
phone: +43 512 507 4726
email: christine.maier@oeaw.ac.at
web: https://quantumoptics.at/

Christian Kokail
Institute of Quantum Optics and Quantum Information
Austrian Academy of Sciences
phone: +43 512 507 4796
email: christian.kokail@oeaw.ac.at
web: https://www.uibk.ac.at/exphys/qo/

Rick van Bijnen
Institute of Quantum Optics and Quantum Information
Austrian Academy of Sciences
phone: +43 512 507 4786
email: rick.van-bijnen@oeaw.ac.at
web: https://www.uibk.ac.at/exphys/qo/

Originalpublikation:

Self-Verifying Variational Quantum Simulation of Lattice Models. C. Kokail*, C. Maier*, R. van Bijnen*, T. Brydges, M. K. Joshi, P. Jurcevic, C. A. Muschik, P. Silvi, R. Blatt, C. F. Roos, and P. Zoller. Nature 2019 DOI: 10.1038/s41586-019-1177-4 https://www.nature.com/articles/s41586-019-1177-4

Dr. Christian Flatz | Universität Innsbruck
Further information:
http://www.uibk.ac.at

More articles from Physics and Astronomy:

nachricht Spinning lightwaves on a one-way street
20.08.2019 | De Gruyter

nachricht A second planet in the Beta Pictoris system
20.08.2019 | CNRS

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 an 'orrery' for quantum gauge theory

Experimental progress towards engineering quantized gauge fields coupled to ultracold matter promises a versatile platform to tackle problems ranging from condensed-matter to high-energy physics

The interaction between fields and matter is a recurring theme throughout physics. Classical cases such as the trajectories of one celestial body moving in the...

Im Focus: A miniature stretchable pump for the next generation of soft robots

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.

Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...

Im Focus: Vehicle Emissions: New sensor technology to improve air quality in cities

Researchers at TU Graz are working together with European partners on new possibilities of measuring vehicle emissions.

Today, air pollution is one of the biggest challenges facing European cities. As part of the Horizon 2020 research project CARES (City Air Remote Emission...

Im Focus: Self healing robots that "feel pain"

Over the next three years, researchers from the Vrije Universiteit Brussel, University of Cambridge, École Supérieure de Physique et de Chimie Industrielles de la ville de Paris (ESPCI-Paris) and Empa will be working together with the Dutch Polymer manufacturer SupraPolix on the next generation of robots: (soft) robots that ‘feel pain’ and heal themselves. The partners can count on 3 million Euro in support from the European Commission.

Soon robots will not only be found in factories and laboratories, but will be assisting us in our immediate environment. They will help us in the household, to...

Im Focus: Scientists create the world's thinnest gold

Scientists at the University of Leeds have created a new form of gold which is just two atoms thick - the thinnest unsupported gold ever created.

The researchers measured the thickness of the gold to be 0.47 nanometres - that is one million times thinner than a human finger nail. The material is regarded...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The power of thought – the key to success: CYBATHLON BCI Series 2019

16.08.2019 | Event News

4th Hybrid Materials and Structures 2020 28 - 29 April 2020, Karlsruhe, Germany

14.08.2019 | Event News

What will the digital city of the future look like? City Science Summit on 1st and 2nd October 2019 in Hamburg

12.08.2019 | Event News

 
Latest News

All-in-one: New microbe degrades oil to gas

20.08.2019 | Life Sciences

Spinning lightwaves on a one-way street

20.08.2019 | Physics and Astronomy

Materials that can revolutionize how light is harnessed for solar energy

20.08.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>