Kondo Effect on Mesoscopic Scale (Review)

TL;DR

This review discusses the Kondo effect in mesoscopic systems, including quantum dots and surface phenomena, highlighting experimental studies, surface anisotropy effects, and theoretical developments in dynamical defects.

Contribution

It synthesizes recent experimental and theoretical advances in understanding the Kondo effect at reduced dimensions and artificial atomic systems.

Findings

STM studies of single magnetic impurities

Reduction of Kondo effect amplitude due to surface anisotropy

Potential two-channel Kondo behavior from dynamical defects

Abstract

Following the discovery of the Kondo effect the bulk transport and magnetic behavior of the dilute magnetic alloys have been successfully described. In the last fifteen years new directions have been developed as the study of the systems of reduced dimensions and the artificial atoms so called quantum dots. In this review the first subject is reviewed starting with the scanning tunneling microscope (STM) study of a single magnetic impurity. The next subject is the reduction of the amplitude of the Kondo effect in samples of reduced dimension which was explained by the surface magnetic anisotropy which blocks the motion of the integer spin nearby the surface. The electron dephasing and energy relaxation experiments are discussed with the possible explanation including the surface anisotropy, where the situation in cases of integer and half-integer spins is very different. Finally, the present situation of the theory of dynamical structural defects is briefly presented which may lead to two-channel Kondo behavior.