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The enigmatic nature of time in quantum mechanics

February 26, 2015 -
3:30pm to 5:00pm
Prof. Y. K. Lau
Institute of Applied Mathematics, Chinese Academy of Mathematics and System Science, Beijing, China

Single photon Sagnac interferometry as a probe to macroscopic quantum mechanics is considered. It is shown that, due to the asymmetric structure of the optical paths traversed by a single photon respectively in the clockwise and counter-clockwise direction within the ring cavity of a Sagnac interferometer, the radiation
pressure force exerted by a photon on a single macroscopic mirror within the cavity generates a linear superposition of temporally  separated quantum states of the mirror,  in contrast to the standard
Schr\"{o}dinger cat involving linear superposition of spatially separated quantum states defined at the same instant of time. Due to the optomechanical coupling of a single photon with  a mirror  within the cavity, the radiation pressure force mediates a  transfer (swapping) of the which path entanglement of the photon to 
the temporally (and not spatially) separated quantum states of the  mirror.  Some fundamental issues related to the enigmatic nature of time in quantum theory and possible quantum gravity  theory raised by the present work are briefly touched upon.

Host: Bei-Lok Hu 

PSC 3150
College Park, MD 20742

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