POSITRONIUM IN ALKALI HALIDES : TUNNELING FROM THE DELOCALIZED TO THE SELF-TRAPPED STATE
POSITRONIUM IN ALKALI HALIDES : TUNNELING FROM THE DELOCALIZED TO THE SELF-TRAPPED STATE
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碱卤化物中的正电子：从离域态隧道到自陷态
DOI：
10.1103/physrevb.57.11341
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发表时间：
1998
影响因子：
3.7
通讯作者：
T. Hyodo
中科院分区：
文献类型：
--
作者：
I. Bondarev;T. Hyodo
利用Nasu和Toyota Zawa发展的激子理论，从理论上研究了正电子(Ps)在碱性卤化物中从其稳定的离域状态到亚稳态的隧道跃迁[J.Phys.SoC。日本。50,235(1981)]。发现这两个态之间的隧穿速率与参数B/ħω(B是Ps带宽的一半，ω是纵向声子的平均频率)成指数关系，而两态之间的势垒高度主要由带宽B决定，并与B成正比。为了从理论上解释Ps自陷的实验数据，提出了一种考虑Ps在离域态和自陷态之间的量子隧穿的拟合方法。该方法得到的Ps自陷参数(隧穿速率和势垒高度)的数值与理论计算的结果定性一致。
The tunnel transition of positronium (Ps) from its stable delocalized state to the metastable localized state in alkali halides is investigated theoretically using the formalism developed by Nasu and Toyozawa for excitons [J. Phys. Soc. Jpn. 50, 235 (1981)]. The tunneling rate between these two states is found to have the exponential dependence on the parameter B/ħ ω (B is half of the Ps bandwidth, ω is the averaged frequency of the longitudinal acoustic phonons), whereas the potential barrier height between the two states is mainly determined by the bandwidth B and is proportional to B. A fitting procedure taking into account the quantum tunneling of Ps between the delocalized and the self-trapped state is proposed for the theoretical interpretation of the experimental data on Ps self-trapping. The procedure yields the numerical values of the parameters of Ps self-trapping (the tunneling rate and the potential barrier height) in qualitative agreement with those calculated theoretically.