Large-N limit of a magnetic impurity in unconventional density waves

TL;DR

This paper studies how an Anderson impurity interacts with an unconventional density wave (UDW), revealing conditions for the Kondo effect, effects on density of states, and phase transitions, with implications for related unconventional condensates.

Contribution

It provides a theoretical analysis of the Kondo effect in UDW systems using large-N techniques, highlighting the influence on density of states and spin susceptibilities.

Findings

Kondo effect occurs only within specific parameter ranges.

UDW influences the low-energy density of states and introduces additional peaks.

A divergence in static spin susceptibility indicates a phase transition.

Abstract

We investigate the effect of unconventional density wave (UDW) condensate on an Anderson impurity using large-N technique at T=0. In accordance with previous treatments of a Kondo impurity in pseudogap phases, we find that Kondo effect occurs only in a certain range of parameters. The f-electron density of states reflects the influence of UDW at low energies and around the maximum of the density wave gap. The static spin susceptibility diverges at the critical coupling, indicating the transition from strong to weak coupling. In the dynamic spin susceptibility an additional peak appears showing the presence the UDW gap. Predictions concerning non-linear density of states are made. Our results apply to other unconventional condensates such as d-wave superconductors and d-density waves as well.