October 2012
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Day October 22, 2012

Time Dependent PT-Symmetric Quantum Mechanics

Jiangbin Gong, Qing-hai Wang

The so-called parity-time-reversal- (PT-) symmetric quantum mechanics (PTQM) has developed into a noteworthy area of research. However, to date most known studies of PTQM focused on the spectral properties of non-Hermitian Hamiltonian operators. In this work, we propose an axiom in PTQM in order to study general time-dependent problems in PTQM, e.g., those with a time-dependent PT-symmetric Hamiltonian and with a time-dependent metric. We illuminate our proposal by examining a proper mapping from a time-dependent Schroedinger-like equation of motion for PTQM to the familiar time-dependent Schroedinger equation in conventional quantum mechanics. The rich structure of the proper mapping hints that time-dependent PTQM can be a fruitful extension of conventional quantum mechanics. Under our proposed framework, we further study in detail the Berry phase generation in a class of PT-symmetric two-level systems. It is found that a closed adiabatic path in PTQM is often associated with an open adiabatic path in a properly mapped problem in conventional quantum mechanics. In one interesting case we further interpret the Berry phase as the flux of a continuously tunable fictitious magnetic monopole, thus highlighting the difference between PTQM and conventional quantum mechanics despite the existence of a proper mapping between them.

Quantum Physics (quant-ph)