STONY BROOK, NY, June 5, 2013 – How can classical behavior emerge from the quantum world? An experimental investigation of this question by the Ultracold Atomic Physics group in the Department of Physics and Astronomy at Stony Brook University was featured in a May 24 editorial, “Experiment investigates how classical physics may emerge from quantum physics,” by the technology news website phys.org.
|Illustration of the simple quantum system consisting of two incommensurate optical lattices that “kick” a macroscopic atomic matter wave (an optically trapped Bose-Einstein condensate). The researchers found that classical behavior emerges naturally in this closed quantum system. Credit: Bryce Gadway, et al.|
The research performed by Bryce Gadway, Jeremy Reeves, Ludwig Krinner and Professor Dominik Schneble – recently published in the journal Physical Review Letters – reports the observation of a quantum-to-classical transition in a periodically driven ultracold atomic gas, suggesting that classical behavior may be an innate property of certain closed quantum systems.
“Thus far, most demonstrations of a quantum-to-classical transition have taken place in open quantum systems, where a purely quantum mechanical subsystem (such as a qubit) is coupled to some macroscopic reservoir with the end result being decoherence of the pure subsystem,” first author Bryce Gadway told phys.org. “This is somewhat artificial because it relies on divorcing the reservoir from the system that decoheres; it assumes that information lost to the reservoir will never be returned,” he said.
“What we’ve been able to show is that such quantum-to-classical transitions can emerge even in the dynamics of simple closed quantum systems,” Gadway said. “By coupling two quantum chaotic subsystems – so-called ‘kicked quantum rotors’ – they both go from being localized due to destructive interference to displaying diffusive energy transport in a completely classical fashion. This is despite the fact that all the dynamics are strictly unitary and time-reversible.”
About Physics and Astronomy at Stony Brook University
The Department of Physics and Astronomy at Stony Brook University offers a diverse program and consistently ranks amongst the best and largest in the country. In their latest departmental rankings (2010), The US News and World listed the department as 23rd in the nation out of 145 programs in the United States; with the Nuclear Physics program ranked 4th. The 2010 NRC ranking which is the most prestigious ranking in the US, ranks the Graduate School among the top 15 programs in the country. The department shares faculty with the CN Yang Institute for Theoretical Physics, a leading center for high energy physics, string theory and statistical mechanics; the Simons Center for Geometry and Physics, a research center devoted to furthering fundamental knowledge in geometry and theoretical physics, especially knowledge at the interface of these two disciplines; and the Laufer Center for Physical and Quantitative Biology, with an aim to advance biology and medicine through discoveries in physics, mathematics and computational science. Current and past faculty members have received numerous top honors in the field, including the Nobel Prize, National Medal of Science, Niels Bohr Institute Prize, Dirac Prize, CAREER Awards, Humboldt Awards, PECASE Awards, Asahi Prize, Dannie Heineman Prize for Mathematical Physics, Guggenheim, Sloan, AAAS, IEEE, American Physical Society and Royal Danish Academy Fellowships, and more.