Condensed Matter Theory

Kondo breakdown in Kondo lattice systems: RKKY versus local spin screening, or: How to measure Eulers constant

Name: Kondo breakdown in Kondo lattice systems: RKKY versus local spin screening, or: How to measure Eulers constant
Start: 2023-04-11T12:00:00+02:00
End: 2023-04-11T13:00:00+02:00
Location: PI

by Johann Kroha (uni-bonn)

Tuesday 11 Apr 2023, 12:00 → 13:00 Europe/Berlin

3.014 (PI)

3.014

PI

Description

The RKKY interaction is a coupling between magnetic impurities in a metal mediated over large distances by the conduction electrons. Its interplay with the local Kondo spin singlet formation can induce quantum phase transitions (QPT) from a heavy Fermi liquid to magnetically ordered phases. However, the RKKY interaction has escaped a systematical treatment due to its indirect, long-range nature. In this talk we discuss an analytic 1-loop renormalization group (RG ) treatment of Kondo breakdown under the influence of the RKKY interaction. Its long-range nature is self-consistently incorporated in the RG in the spirit of a dynamical mean-field theory. The theory predicts a universal suppression of the Kondo scale at the QPT in agreement with experiments on two-impurity Kondo systems. It suggests a rather complicated way for "measuring" Euler's constant.