Australian and German researchers have collaborated to develop a genetic algorithm to confirm the rejection of classical notions of causality.

Dr Alberto Peruzzo from RMIT University in Melbourne said: "Bell's theorem excludes classical concepts of causality and is now a cornerstone of modern physics.

"But despite the fundamental importance of this theorem, only recently was the first 'loophole-free' experiment reported which convincingly verified that we must reject classical notions of causality.

"Given the importance of this data, an international collaboration between Australian and German institutions has developed a new method of analysis to robustly quantify such conclusions."

The team's approach was to use genetic programming, a powerful machine learning technique, to automatically find the closest classical models for the data.

Together, the team applied machine learning to find the closest classical explanations of experimental data, allowing them to map out many dimensions of the departure from classical that quantum correlations exhibit.

Dr Chris Ferrie, from the University of Technology Sydney, said: "We've light-heartedly called the region mapped out by the algorithm the 'edge of reality,' referring to the common terminology 'local realism' for a model of physics satisfying Einstein's relativity.

"The algorithm works by building causal models through simulated evolution imitating natural selection - genetic programming.

"The algorithm generates a population of 'fit' individual causal models which trade off closeness to quantum theory with the minimisation of causal influences between relativistically disconnected variables."

The team used photons, single particles of light, to generate the quantum correlations that cannot be explained using classical mechanics.

Quantum photonics has enabled a wide range of new technologies from quantum computation to quantum key distribution.

The photons were prepared in various states possessing quantum entanglement, the phenomenon which fuels many of the advantages in quantum technology. The data collected was then used by the genetic algorithm to find a model that best matches the observed correlations.

These models then quantify the region of models which are ruled out by nature itself.

The team includes theoretical physicists and computer scientists from the ARC Centre for Engineered Quantum Systems (EQuS) at the University of Sydney, the Centre for Quantum Software and Information at the University of Technology Sydney and the Institute for Theoretical Physics at the University of Cologne as well as the experimental group at RMIT University's Quantum Photonics Laboratory. The research, "Explaining quantum correlations through evolution of causal models", has been published in Physical Review A and can be accessed online.

Tweet

Detector delivery marks another Euclid milestone
Paris (ESA) Apr 27, 2017
ESA's Euclid mission has passed another important milestone with the delivery of the first three state-of-the art detectors for the Near-Infrared Spectrometer and Photometer instrument. Euclid is a pioneering mission to observe billions of faint galaxies and investigate the origin of the Universe's accelerating expansion, as well as the mysterious nature of dark energy, dark matter and gra ... read more

Related Links
RMIT University
Understanding Time and Space

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only