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Relative criterion for validity of a semiclassical approach to the dynamics near quantum critical points
Qian Wang1, Pinquan Qin2, Wen-ge Wang1
1Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.
Abstract:
Based on an analysis of Feynman's path integral formulation of the propagator, a relative criterion is proposed for validity of a semiclassical approach to the dynamics near critical points in a class of systems undergoing quantum phase transitions. It is given by an effective Planck constant, in the relative sense that a smaller effective Planck constant implies better performance of the semiclassical approach. Numerical tests of this relative criterion are given in the XY model and in the Dicke model.
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