Effects of Berry phase and instantons in one dimensional Kondo-Heisenberg model

摘要

Motivated by the global phase diagram of antiferromagnetic heavy-fermionmetals, we study the Kondo effect from the perspective of a nonlinear sigmamodel in the one dimensional Kondo-Heisenberg model. We focus on the effects ofthe instanton configurations of the sigma-model field and the associated Berryphase. Guided by the results derived using bosonization methods, we demonstratethat the Kondo singlet formation is accompanied by an emergent Berry phase.This Berry phase also captures the competition between the Kondo-singletformation and spin Peierls correlations. Related effects are likely to berealized in Kondo lattice systems in higher dimensions.