A new optical field state as an output of diffusion channel when the input being number state  

作　　者：FAN HongYi LOU SenYue PAN XiaoYin HU LiYun 

机构地区：[1]Department of Physics, Ningbo University [2]Department of physics, Jiangxi Normal University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第9期1649-1653,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11175113 and 11264018);the Natural Science Foundation of Jiangxi Province of China(Grant No 20132BAB212006)

摘　　要：By analyzing theoretical scheme of quantum controlling through photon addition,we propose a new optical field whose density operator asρ=λ(1-λ)l:Ll(-λ2aa/1-λ)e-λaa:(here::denotes normal ordering symbol),which is named Laguerre-polynomialweighted chaotic state.We show that such state is the solution to the master equation d/dtρ=-κ(aaρ+ρaa-aρa-aρa),describing a diffusion channel,with the initial number state|l l|,andλ=1/(1+κt).This new state is characteristic of possessing photon number l+κt at time t,so the photon number by adjusting the diffusion parameterκcan be controlled.This master equation is solved using the summation method within ordered product of operators and the entangled state representation.The physical difference between the diffusion and the amplitude damping is noted.By analyzing theoretical scheme of quantum controlling through photon addition,we propose a new optical field whose density operator asρ=λ（1-λ）^l：Ll（-λ2aa/1-λ）e^-λaa：（here：：denotes normal ordering symbol）,which is named Laguerre-polynomialweighted chaotic state.We show that such state is the solution to the master equation d/dt ρ=-κ（aaρ＋ρaa-aρa-aρa）,describing a diffusion channel,with the initial number state｜l l｜,andλ=1/（1＋κt）.This new state is characteristic of possessing photon number l＋κt at time t,so the photon number by adjusting the diffusion parameterκcan be controlled.This master equation is solved using the summation method within ordered product of operators and the entangled state representation.The physical difference between the diffusion and the amplitude damping is noted.

关 键 词：photon addition Laguerre-polynomial-weighted chaotic state entangled state representation 

分 类 号：O431.2[机械工程—光学工程]