液氦薄膜表面电子-涟波子系统的有效质量

Effective Mass of the Electron-Ripplon System on the Surface of Liquid Helium Films

研究了液氦薄膜表面电子与涟波子弱耦合的性质 ,采用线性组合算符和微扰法导出电子 涟波子系统的有效质量。当计及电子在反冲效应中发射和吸收不同波矢的涟波子之间相互作用时 ,讨论对电子

The properties of the electron-ripplon system on the surface of liquid helium film influence the properties of liquid helium very markedly.The problem of a two-dimensional electron on the surface of a liquid helium film was formulated by Jackson and Platzaman as a surface polaron problem.The properties of eleron-ripplon system on the surface of liquide helium film have been of considerable interest.The surface polaron in the eletron-ripplon system is investigated by Tokuda within the modified variational scheme of the Lee-Low-Pines theory which is valid for the whole range of the eletron-ripplon coupling.Jackson and Peeters have applied and extension of the Feynman path-integral formalism to the problem of noninteracting polaronic electron on the surface of a liquid helium film in a perpendicularly applied magnetization field. The ground state energy, the Feynman-model mass,the magnetization,and susceptibility of the system are calculated.The Landau-pekar variational theory for investigating the strong-coupling system of electron-phonon in crystals is employed by Jin Pei-wan et al.to study the system of an electron strongly coupled to ripplons on the outer surface of the liquid-helium film.Analytical expressions of the ground state energy,the effective mass,and the average number of virtual ripplons around the electron are obtained.Huybrechts proposed a linear combination operator method,by which a strong-coupling polaron was investigated.On the basis of Huybrechts' work,Tokuca added another variational parameter to the momentum operator and also evaluated the ground-state energy and effective mass of the bulk polaron.In fact,so far research on the electron-ripplon system has been restricted to approximation and calculation where the interaction between ripplons of different wave vectors in the recoil process in neglected.The properties of the surface magnetopolaron and the surface polaron, considering the corresponding interaction,have been discussed by the present authors.The effect of the interaction between ripplons of different wave vectors in he recoil process on the effective mass of the electron-ripplon system are studied by using linear combination operator and pertur- bation method in this paper.