量子熵及其在生物光子学中的应用

摘要

基于光子场与声子库的相互作用机制,建立一个量子光学模型来描述“薛定谔猫”态所诱导的非经典效应的动力学演化.研究光场的量子统计性质(包括光子数分布、平均光子数、光子数方差和光场起伏),讨论了光场量子熵的时间演化,涉及Shannon熵、Wehrl熵及光子统计熵.研究表明,这三种熵在描述光场的量子统计性质方面是相互等价的,而光子统计熵具有可测量的特点,因此光子统计熵的概念和表述被用来研究生物光子辐射的相干性问题.通过测量新鲜树叶和一个非生命天然辐射体的自发光子辐射,对比分析相应的光子数方差及光子统计熵.结果表明,生物光子辐射具有高度的相干性.经考察衰变过程中的生物光子辐射相干性,并与稳态情况相比较,发现两者高度一致.特别是,可采用统一的表达式拟合衰变和稳态两种情况下场熵G(N)随平均光子数N的变化.作为应用,测量了转基因黄豆的自发光子辐射,并与相应的传统样品相比较,发现两者在光子统计熵的意义上有显著区别.%A quantum optical model has been presented for the description of biophoton activity,which is based on the quantum theory of the interaction of a photon field with a phonon reservoir.The model is used to analyze the dynamics of the nonclassical effects induced by the Schr(o)dinger-cat-state,especially involving the aspects of quantum entropy of light field,including Shannon entropy,Wehrl entropy and the photon statistical entropy.In particular,the photon statistical entropy is predicted to be able to characterize coherence properties of biophotons,which can be obtained by means of measurement of spontaneous emission from the samples.Experiments on a leaf are then performed and compared with a non-living radiator; the biophotons are found to have significantly higher coherence than the ordinary light.As an application,biophoton emission of the soybean samples with and without genetic treatment is investigated,and the significant difference between them is found out in terms of the photon statistical entropy.