Quantum experiments designed by machines

February 22, 2016

Quantum physicist Mario Krenn and his colleagues in the group of Anton Zeilinger from the Faculty of Physics at the University of Vienna and the Austrian Academy of Sciences have developed an algorithm which designs new useful quantum experiments. As the computer does not rely on human intuition, it finds novel unfamiliar solutions. The research has just been published in the journal Physical Review Letters.

The idea was developed when the physicists wanted to create new quantum states in the laboratory, but were unable to conceive of methods to do so. "After many unsuccessful attempts to come up with an experimental implementation, we came to the conclusion that our intuition about these phenomena seems to be wrong. We realized that in the end we were just trying random arrangements of quantum building blocks. And that is what a computer can do as well - but thousands of times faster", explains Mario Krenn, PhD student in Anton Zeilinger's group and first author research.

After a few hours of calculation, their algorithm - which they call Melvin - found the recipe to the question they were unable to solve, and its structure surprised them. Zeilinger says: "Suppose I want build an experiment realizing a specific quantum state I am interested in. Then humans intuitively consider setups reflecting the symmetries of the state. Yet Melvin found out that the most simple realization can be asymmetric and therefore counterintuitive. A human would probably never come up with that solution."

The physicists applied the idea to several other questions and got dozens of new and surprising answers. "The solutions are difficult to understand, but we were able to extract some new experimental tricks we have not thought of before. Some of these computer-designed experiments are being built at the moment in our laboratories", says Krenn.

Melvin not only tries random arrangements of experimental components, but also learns from previous successful attempts, which significantly speeds up the discovery rate for more complex solutions. In the future, the authors want to apply their algorithm to even more general questions in quantum physics, and hope it helps to investigate new phenomena in laboratories.
-end-
The research was supported by Austrian Academy of Sciences (ÖAW), the European Research Council (SIQS Grant No. 600645 EUFP7-ICT), the Austrian Science Fund (FWF) with SFB F40 (FOQUS).

Publication in Physical Review Letters

Mario Krenn, Mehul Malik, Robert Fickler, Radek Lapkiewicz, Anton Zeilinger: Automated Search for new Quantum Experiments, Physical Review Letters, 22 February, 2016 http://arxiv.org/abs/1509.02749

University of Vienna

Related Quantum Physics Articles from Brightsurf:

Know when to unfold 'em: Applying particle physics methods to quantum computing
Borrowing a page from high-energy physics and astronomy textbooks, a team of physicists and computer scientists at Berkeley Lab has successfully adapted and applied a common error-reduction technique to the field of quantum computing.

Quantum physics: Physicists successfully carry out controlled transport of stored light
A team of physicists at Mainz University has successfully transported light stored in a quantum memory over a distance of 1.2 millimeters.

New system detects faint communications signals using the principles of quantum physics
Researchers at the National Institute of Standards and Technology (NIST) have devised and demonstrated a system that could dramatically increase the performance of communications networks while enabling record-low error rates in detecting even the faintest of signals.

Quirky response to magnetism presents quantum physics mystery
In a new study just published and highlighted as an Editor's Suggestion in Physical Review Letters, scientists describe the quirky behavior of one such magnetic topological insulator.

Evidence of power: Phasing quantum annealers into experiments from nonequilibrium physics
Scientists at Tokyo Institute of Technology (Tokyo Tech) use commercially available quantum annealers, a type of quantum computer, to experimentally probe the validity of an important mechanism from nonequilibrium physics in open quantum systems.

Adapting ideas from quantum physics to calculate alternative interventions for infection and cancer
Published in Nature Physics, findings from a new study co-led by Cleveland Clinic and Case Western Reserve University teams show for the first time how ideas from quantum physics can help develop novel drug interventions for bacterial infections and cancer.

Quantum physics: Realization of an anomalous Floquet topological system
An international team led by physicists from the Ludwig-Maximilians Universitaet (LMU) in Munich realized a novel genuine time-dependent topological system with ultracold atoms in periodically-driven optical honeycomb lattices.

Quantum physics provides a way to hide ignorance
Students can hide their ignorance and answer questions correctly in an exam without their lack of knowledge being detected by teachers -- but only in the quantum world.

Quantum physics: Physicists develop a new theory for Bose-Einstein condensates
Bose-Einstein condensates are often described as the fifth state of matter: At extremely low temperatures, gas atoms behave like a single particle.

Attosecond physics: Quantum brakes in molecules
Physicists have measured the flight times of electrons emitted from a specific atom in a molecule upon excitation with laser light.

Read More: Quantum Physics News and Quantum Physics Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.