Hidden non-Fermi liquid behavior due to crystal field quartet

Abstract

We study a realistic Kondo model for crystal field quartet ground states having magnetic and non-magnetic (quadrupolar) exchange couplings with conduction electrons, using the numerical renormalization group method. We focus on a local effect dependent on singlet excited states coupled to the quartet, which reduces the non-magnetic coupling significantly and drives non-Fermi liquid behavior observed in the calculated quadrupolar susceptibility. A crossover from the non-Fermi liquid state to the Fermi liquid state is characterized by a small energy scale very sensitive to the non-magnetic coupling. On the other hand, the Kondo temperature observed in the magnetic susceptibility is less sensitive. The different crystal-field dependence of the two exchange couplings may be related to the different $x$ dependence of quadrupolar and magnetic ordering temperatures in Ce${}_x$La${}_{1-x}$B${}_6$.

7 pages, 5 EPS figures, REVTeX

References in corpus (3)

• Evidence for a common physical description of non-Fermi-liquid behavior in f-electron systems
• Crystal Field Triplets: A New Route to Non-Fermi Liquid Physics
• Charge Kondo effect toward a non-Fermi-liquid fixed point in the orbitally degenerate exchange model

Cited by in corpus (4)

• The numerical renormalization group method for quantum impurity systems
• Two-channel Kondo Effect Emerging from Nd Ions
• Critical Nature of Non-Fermi Liquid in Spin 3/2 Multipolar Kondo Model
• Quantum Critical Point between Two-Channel Kondo and Fermi-Liquid Phases