双光子Jaynes-Cummings模型中光场的熵压缩

研究传统的光场压缩效应一般从海森伯(Heisenberg)测不准关系出发,应用均方根(RMS)偏差量度光场的量子涨落.由于均方根偏差只涉及光场密度矩阵的二阶统计矩,在许多情况下,这种物理量不能精确量度光场的量子涨落.海森伯测不准关系是熵测不准关系的一个特例,可用熵量度光场正交分量的量子涨落.依据熵测不准关系,建立了光场熵压缩的概念.研究了双光子杰内斯-卡明(Jaynes-Cummings(J-C))模型中光场的熵压缩规律.对比发现,熵指数δxf(t)比均方根偏差△xf(t)更敏感于光场的压缩效应,是量度光场的压缩效应的高灵敏度物理量.

Entropic Squeezing of the Optical Field in the Two-Photon Jaynes-Cummings Model

Traditional researches on the squeezing effect of optical field are based on Heisenberg′s uncertainty principle and use root mean square (RMS) deviation to measure the quantum fluctuation of optical field. However, RMS deviation only contains the second-order statistical moments of the density operator. Thus under many circumstances, RMS deviation cannot precisely measure the quantum fluctuation. In fact, Heisenberg′s uncertainty principle is a special case of entropy uncertainty relation, and entropy can be used to measure the quantum fluctuation of the quadrature components of the field. Based on entropy uncertainty relation, the concept of entropy squeezing has been formulated. Entropy squeezing of the optical field in two photon Jaynes-Cummings (J-C) model is discussed. By comparing, it is found that the entropy exponential δxf(t) is more sensitive to the squeezing effect of optical field than the RMS deviation Δxf(t), and is a high sensitive parameter to measure optical field.