Analytical and numerical investigations of displaced thermal state evolutions in a laser process  

作　　者：杜传勋 孟祥国 张冉 王继锁 

机构地区：[1]Shandong Provincial Key Laboratory of Laser Polarization and Information Technology, College of Physics and Engineering,Qufu Normal University [2]School of Physical Science and Information Engineering, Liaocheng University

出　　处：《Chinese Physics B》2017年第12期102-108,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11347026);the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2016AM03 and ZR2017MA011)

摘　　要：We investigate how displaced thermal states （DTSs） evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly classical thermal field only related to the laser parameters κ and g. The normal ordering product of density operator of the DTS in the laser channel leads to obtaining the analytical time-evolution expressions of the photon number, Wigner function, and von Neumann entropy. Also, some interesting results are presented via numerically investigating these explicit time-dependent expressions.We investigate how displaced thermal states （DTSs） evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly classical thermal field only related to the laser parameters κ and g. The normal ordering product of density operator of the DTS in the laser channel leads to obtaining the analytical time-evolution expressions of the photon number, Wigner function, and von Neumann entropy. Also, some interesting results are presented via numerically investigating these explicit time-dependent expressions.

关 键 词：displaced thermal state laser process infinitive operator-sum representation photon number Wigner function von Neumann entropy 

分 类 号：TN24[电子电信—物理电子学]