Critical Nature of Non-Fermi Liquid in Spin 3/2 Multipolar Kondo Model

TL;DR

This paper investigates a multipolar Kondo model with spin 3/2 impurities interacting with conduction electrons, revealing a non-Fermi liquid state with unique thermodynamic properties using boundary conformal field theory.

Contribution

It introduces a novel spin 3/2 multipolar Kondo model and explicitly derives a two-channel Kondo-like non-Fermi liquid fixed point via superspin absorption in a hidden SO(5) symmetry sector.

Findings

Identifies a non-Fermi liquid fixed point distinct from the usual spin-1/2 2CK model.

Shows the impurity specific heat is proportional to temperature at low temperatures.

Highlights differences in low-temperature behavior compared to conventional models.

Abstract

A multipolar Kondo model of an impurity spin S_I=3/2 interacting with conduction electrons with spin s_c=3/2 is investigated using boundary conformal field theory. A two-channel Kondo (2CK) -like non-Fermi liquid (NFL) under the particle-hole symmetry is derived explicitly using a ``superspin absorption'' in the sector of a hidden symmetry, SO(5). We discuss the difference between the usual spin-1/2 2CK NFL fixed point and the present one. In particular, we find that, unlike the usual 2CK model, the low temperature impurity specific heat is proportional to temperature.