Hybridization oscillation in the one-dimensional Kondo-Heisenberg model with Kondo holes

Neng Xie,Danqing Hu,Yi-Feng Yang

doi:10.1038/s41598-017-12240-7

Abstract

We use the density matrix renormalization group method to study the properties of the one-dimensional Kondo-Heisenberg model doped with Kondo holes. We find that the perturbation of the Kondo holes to the local hybridization exhibits spatial oscillation pattern and its amplitude decays exponentially with distance away from the Kondo hole sites. The hybridization oscillation is correlated with both the charge density oscillation of the conduction electrons and the oscillation in the correlation function of the Heisenberg spins. In particular, we find that the oscillation wavelength for intermediate Kondo couplings is given by the Fermi wavevector of the large Fermi surface even before it is formed. This suggests that heavy electrons responsible for the oscillation are already present in this regime and start to accumulate around the to-be-formed large Fermi surface in the Brillouin zone.

Highlights

Heavy fermion materials exhibit many exotic quantum phenomena such as unconventional superconductivity[1,2,3] and unconventional quantum criticality[4,5,6]
Theoretical calculations based on the mean-field approximation predicted a spatial oscillation of the hybridization with a characteristic wavelength determined by the Fermi wavevector of the so-called small Fermi surface of unhybridized conduction electrons[13], which seems to be confirmed by later scanning tunneling microscopy (STM) experiment on Th-doped URu2 Si2 at very low temperature in the hidden order phase[16]
Bearing in mind the limitation of the mean-field approximation, we examine the above results by applying the density matrix renormalization group (DMRG) method[18,19,20] to the one-dimensional (1D) Kondo-Heisenberg model doped with Kondo holes

Summary

Introduction

Heavy fermion materials exhibit many exotic quantum phenomena such as unconventional superconductivity[1,2,3] and unconventional quantum criticality[4,5,6]. For both intermediate and strong couplings, we find that the local hybridization, the conduction electron charge density, and the correlation function of the Heisenberg spins are all entangled and exhibit similar oscillation pattern.

Results

Conclusion