The Kondo Screening Cloud around a Quantum Dot: Large-scale numerical Results

TL;DR

This paper provides large-scale numerical evidence for the Kondo screening cloud around a quantum dot, confirming RG predictions and exploring effects of symmetry breaking using advanced computational methods.

Contribution

It presents the first extensive numerical results on the Kondo screening cloud, validating RG theories and analyzing symmetry breaking effects.

Findings

Numerical confirmation of weak to strong coupling crossover

Universal scaling functions for the Kondo cloud

Impact of particle-hole symmetry breaking

Abstract

Measurements of the persistent current in a ring containing a quantum dot would afford a unique opportunity to finally detect the elusive Kondo screening cloud. We present the first large-scale numerical results on this controversial subject using exact diagonalization and density matrix renormalization group (RG). These extremely challenging numerical calculations confirm RG arguments for weak to strong coupling crossover with varying ring length and give results on the universal scaling functions. We also study, analytically and numerically, the important and surprising effects of particle-hole symmetry breaking.