1、38 7 2009 M7null null null null null null null null null null null null;null0nullnullACTA PHOTONICA SINICAVol. 38 No.7July 2009*福建省自然科学基金(T0650013)资助Tel:0599-5136577null Email:daominglu79hotmail. com收稿日期:2008-02-03null null 修回日期: 2008-05-26;0J-C q HWM r*卢道明(K0“,yK 354300)Knull1:利用多光子J-C模型,考虑场频率随时间以正
2、弦函数形式作小量变化,在旋波近似下,研究了二能级原子通过多光子跃迁与单模辐射场相互作用系统中场的压缩效应.利用数值计算方法讨论了场频率变化的幅值和角频率a以及光场强度对场压缩效应的影响.结果表明:随场频率变化的幅值增大,场压缩效应增强;随光场初始平均光子数的增加,场压缩效应减弱.场正交分量的均方涨落随时间的演化受场频率随时间正弦函数形式变化的调制,场频率变化的幅值越大调制作用越强.1oM:二能级原子;J-C模型;频率变化场;压缩效应ms |: O431.2 null null null nullDS M :A null null null nullcI|:1004-4213(2009)07-1
3、840-60 null;0MT“d 0+ 0; = . ; r, Q B d+,7 OS 0K ; ,.Y, |_# 0Y 5“ null9v, ( null/2)2/( null+ null+1 )(null/ 2)2/ ( null+ null+2 )99v, T(12)Q1B ( null/2) 2/( null+ null+2 )BQZ9v,7 ( null/2)2/( null+ null+1 )=QZ9v,yN u9v,Q1|hl.3.1null qMu rY qMuM rY.YV 9 , |k= 3, w = g0, null01 =1000 g0,; (;0 n0= 1. 0,
4、 usY |0, g0,10.0 g0, 20.0 g0, 40. 0 g0,80.0 g0 H, Q1 wLnm1. 1 n,m ( Q1= 0L.m1(a)u= 0,V U q O0 % q f .Vm1 Vn: qMu l H, qM rYl. qMu9v, qM rYv9 . k= 3, null01= 1 000 g0, u= 80. 0 g0, w= 1g0, n0= 20, usY |040 g0 H, Q1 wLnm4.m4V .1843;null0nullnull38 4 null S;0J-C $ ,o /,SJ-C w l, # W,. T/= ?)0;0V0 rJ.;0
5、,1999,28(11):1066-1070.7 null XU Jing-ping, YANG Ya-ping. The interactions between anatom and a field with a time-varying frequency J. ActaPhysica Sinica,2004,53(7):2139-2144. , . qM H0MTJ. ,2004,53(7):2139-2144.8 null LU Dao-ming. Evolution of field entropy with a time-varying18447 S :;0J-C q HWM r
6、frequency in the multiphoton Jaynes-Gummings model J.Acta photonica sinica,2007,36(11):2142-2147.S .0 q HWMMT“dJ.;0,2007,36(11):2142-2147.Squeezing Effects of Field with a Time-Varying Frequencyin theMultiphoton Jaynes-Cummings ModelLU Dao-Ming(Department of Electronic Engineering, Wuyi University,W
7、uyishan, Fujian,354300,China)Abstract:Using the multiphoton Jaynes-Cummings model,the squeezing effect of the field in the system ofa two-level atom interacting with the single mode coherent field through mutiphoton transition wasstudied. The frequency of the field varying with time in the form of s
8、ine was considered.The influences ofamplitude and angular frequency of the field-frequency variation on squeezing effects of the field werediscussed by numericalcalculations. The influencesofmean photon number of the fieldonsqueezing effectsof the field were also discussed. Calculation results indic
9、ate that the squeezing effects of field strengthenswith the increase of the amplitude u of field-frequency variation and weaken with the increase of meanphoton number of the field.The time-evolution behavior of quadrature squeezing function Q1 is modulatedby the field-frequency variation.The modulat
10、ion intensity isenchanced with the increase of theamplitude uof field-frequency variation, and when the amplitude u of field-frequency variation is larger than a fixedvalue, the time-evolution of quadrature squeezing function Q1 will display quas-iperiodicity oscillationbehavior. Its oscillation fre
11、quency agreeswith the angular frequency of field-frequency variation.Key words:Two-level atom;Jaynes-Commings model;Field with time-varying frequency;Squeezing effectLU Dao-mingnull was born in 1963 and received his M.S.degree in department of physics fromNanjing University in 1988. He is a professor of physics in Wuyi University. His mainresearch focuses on quantum optics.1845
