T−Jring with an Anderson impurity: A model for a quantum dot

Abstract

A quantum wire of finite length L with correlated electrons coupled to a quantum dot is studied. The wire is parametrized in terms of the supersymmetric $t\ensuremath{-}J$ model and the dot is represented by an Anderson-like impurity. The model is integrable and we discuss the properties of the finite chain by solving the Bethe Ansatz equations. For a finite ring the energy spectrum is discrete and has to be obtained numerically. As a function of the coupling of the dot to the wire we discuss the ground state and low-energy excitations, the Aharonov-Bohm oscillations and the discontinuities of the magnetization of the system.