量子光学学报
量子光學學報
양자광학학보
ACTA SINICA QUANTUM OPTICA
2009年
3期
215-220
,共6页
相位损耗腔%Raman相互作用%相干态光场%Pegg-Barnett相位
相位損耗腔%Raman相互作用%相榦態光場%Pegg-Barnett相位
상위손모강%Raman상호작용%상간태광장%Pegg-Barnett상위
JCM with Raman coupling%Pegg-Barnett phase%coherent field%phase damped cavity
利用Pegg-Barnett相位理论,研究了耗散腔中两个A型原子与相干态光场在Raman相互作用下光场的相位特性,并讨论了光场平均光子数和腔场耗散系数对光场相位特性的影响.结果表明:当腔不存在损耗时,光场相位分布概率以π/λ作周期性振荡;且在t=nπ/λ时刻,光场和原子是退纠缠的,相位分布概率曲线在极坐标图中呈单叶型结构;但在演化周期内,由于光场与原子的相互作用相位分布概率曲线会劈裂为多叶型结构.当腔场存在损耗时,相位分布概率的叶型结构会向中心扩散最终变为一个圆,即表明在考虑腔场耗散时光场的相位最终会变为随机分布;而且腔的耗散系数越大,光场相位越快趋于随机分布.另外,随光场的平均光子数增大,光场相位分布趋于集中.光场相位涨落受到腔场耗散的影响呈现出衰减周期振荡最终达到稳定值,而且达稳定值所需时间随耗散系数的增大而缩短.
利用Pegg-Barnett相位理論,研究瞭耗散腔中兩箇A型原子與相榦態光場在Raman相互作用下光場的相位特性,併討論瞭光場平均光子數和腔場耗散繫數對光場相位特性的影響.結果錶明:噹腔不存在損耗時,光場相位分佈概率以π/λ作週期性振盪;且在t=nπ/λ時刻,光場和原子是退糾纏的,相位分佈概率麯線在極坐標圖中呈單葉型結構;但在縯化週期內,由于光場與原子的相互作用相位分佈概率麯線會劈裂為多葉型結構.噹腔場存在損耗時,相位分佈概率的葉型結構會嚮中心擴散最終變為一箇圓,即錶明在攷慮腔場耗散時光場的相位最終會變為隨機分佈;而且腔的耗散繫數越大,光場相位越快趨于隨機分佈.另外,隨光場的平均光子數增大,光場相位分佈趨于集中.光場相位漲落受到腔場耗散的影響呈現齣衰減週期振盪最終達到穩定值,而且達穩定值所需時間隨耗散繫數的增大而縮短.
이용Pegg-Barnett상위이론,연구료모산강중량개A형원자여상간태광장재Raman상호작용하광장적상위특성,병토론료광장평균광자수화강장모산계수대광장상위특성적영향.결과표명:당강불존재손모시,광장상위분포개솔이π/λ작주기성진탕;차재t=nπ/λ시각,광장화원자시퇴규전적,상위분포개솔곡선재겁좌표도중정단협형결구;단재연화주기내,유우광장여원자적상호작용상위분포개솔곡선회벽렬위다협형결구.당강장존재손모시,상위분포개솔적협형결구회향중심확산최종변위일개원,즉표명재고필강장모산시광장적상위최종회변위수궤분포;이차강적모산계수월대,광장상위월쾌추우수궤분포.령외,수광장적평균광자수증대,광장상위분포추우집중.광장상위창락수도강장모산적영향정현출쇠감주기진탕최종체도은정치,이차체은정치소수시간수모산계수적증대이축단.
By means of Pegg and Barnett phase formalism, the phase properties of the field interacting with two A-type three-level atoms via Raman coupling in a phase damped cavity is discussed. The influences of decay coefficient of the cavity and the intensity of the field on the phase distribution as well as its fluctuation are discussed. The results show: if there is absence of the phase damping, the phase distribution oscillates with the period π/λ. It presents single leaf at t=nπ/λ, but it splits into multi-leaf construction during the evolution period due to the interaction between the field and the atoms. If there is presence of the phase damping, the obvious leaf construction of the phase distribution become obscure and contract into a circle, which indicates the random distribution of the phase. Moreover, the larger the decay coefficient is, the more rapidly the phase becomes random distribution. The narrowing of the leaf and the increasing amplitude of the phase distribution corresponds to a stronger field. The phase fluctuation shows damped oscillatory behavior and ultimately reaches a steady value in the phase damped cavity. The time for it to approach the steady value shortens when decay coefficient increases.