摘要
By introducing the Dzyaloshinsky-Moriya （DM） interaction, the Loschmidt Echo （LE） of a quantum sys- tem consisting of a central spin and its surrounding environment characterized by an XY spin chain was investigated analytically and numerically. At the critical points of the magnetic field, the LE presents an obvious decay. The decay amplitude can be tuned by the DM interaction. In some specific intervals the DM interaction can remarkably delay the decay of the LE. On the other hand, the DM interaction can change the effects of the anisotropy parameter on the LE.
By introducing the Dzyaloshinsky-Moriya （DM） interaction, the Loschmidt Echo （LE） of a quantum sys- tem consisting of a central spin and its surrounding environment characterized by an XY spin chain was investigated analytically and numerically. At the critical points of the magnetic field, the LE presents an obvious decay. The decay amplitude can be tuned by the DM interaction. In some specific intervals the DM interaction can remarkably delay the decay of the LE. On the other hand, the DM interaction can change the effects of the anisotropy parameter on the LE.
基金
Supported by Scientific Research Project for Shaanxi Provincial Department of Education(12Jk0957)
Science Foundation of Xi’an University of Posts and Telecommunications(1050409,1051206)
