Ground-state description of quasi-one-dimensional polarons with arbitrary electron-phonon coupling strength

摘要

We consider the interaction of a confined electron with bulk polar-optical phonons in a cylindrical quantum well wire with infinite boundary potential. Expressions for the polaron self-energy and mass are derived within a variational scheme over reasonably broad ranges of the wire radius and the phonon-coupling strength. The formulation is based on the standard canonical transformation of the strong-coupling ansatz and consists of a variationally determined perturbative extension serving for the theory to interpolate in the overall range of the coupling constant. Contrary to the general trend that the electron-phonon interaction is inherently stronger in systems of lower dimensionality, our results indicate that, at weak coupling, the binding energy of the polaron can be smaller and its mass less inertial compared with the bulk case when the wire is made narrow.