Universal behavior of quantum impurity scattering in a Tomonaga-Luttinger liquid

[摘要] Using bosonization and path-integral methods, we study general low-temperature behavior of nonmagnetic and magnetic impurity scattering in Tomonaga-Luttinger liquid, and calculate the electron Green function for a general backward scattering potential. We demonstrate that the electron density of state near the impurity site is suppressed by backward scattering, but it mainly remains invariant far away from the impurity, and that at zero temperature the electrons are completely reflected on the impurity site; the system breaks into two subsystems, but right- and left-moving electron fields have a twisted boundary condition. We also show that a testing charge can only be partially screened by conduction electrons, and in a strong interaction region the impurity susceptibility has a 1/T-type low-temperature behavior. [S0163-1829(99)11111-1].

[关键词] FERMI-EDGE SINGULARITY;DIMENSIONAL ELECTRON-GAS;CONFORMAL FIELD-THEORY;DENSITY-OF-STATES;QUANTIZED CONDUCTANCE;MAGNETIC IMPURITY;KONDO PROBLEM;MODEL;BACKSCATTERING;ENHANCEMENT