Single-impurity Kondo physics at extreme particle-hole asymmetry

Abstract

We study the fate of the Kondo effect with one-dimensional conduction baths at very low densities, such that the system explores the bottom of the conduction band. This can involve either finite low densities, or a small number of fixed conduction electrons in a large system, i.e., the limit of large bath sizes can be taken with either fixed small density or with fixed number. We characterize the Kondo physics for such systems through the energy gain due to Kondo coupling, which is a general analog of the Kondo temperature scale, and through real-space profiles of densities and spin-spin correlation functions.