Evolution of the Kondo state of YbRh2Si2 probed by high field ESR

Abstract

An electron spin resonance (ESR) study of the heavy fermion compound YbRh2Si2 for fields up to ~ 8 T reveals a strongly anisotropic signal below the single ion Kondo temperature T_K ~ 25 K. A remarkable similarity between the T-dependence of the ESR parameters and that of the specific heat and the 29Si nuclear magnetic resonance data gives evidence that the ESR response is given by heavy fermions which are formed below T_K and that ESR properties are determined by their field dependent mass and lifetime. The signal anisotropy, otherwise typical for Yb{3+} ions, suggests that, owing to a strong hybridization with conduction electrons at T < T_K, the magnetic anisotropy of the 4f states is absorbed in the ESR of heavy quasiparticles. Tuning the Kondo effect on the 4f states with magnetic fields ~ 2 - 8 T and temperature 2 - 25 K yields a gradual change of the ESR g-factor and linewidth which reflects the evolution of the Kondo state in this Kondo lattice system.

new substantially revised version

References in corpus (3)

• Quantum Criticality in Heavy Fermion Metals
• Relevance of ferromagnetic correlations for the Electron Spin Resonance in Kondo lattice systems
• Electron spin resonance in Kondo systems

Cited by in corpus (6)

• Microwave spectroscopy on heavy-fermion systems: probing the dynamics of charges and magnetic moments
• Cryogenic frequency-domain electron spin resonance spectrometer based on coplanar waveguides and field modulation
• Optimization of Coplanar Waveguide Resonators for ESR Studies on Metals
• Effect of pressure on the Electron Spin Resonance of a Heavy-Fermion metal
• Angle-dependent electron spin resonance of YbRh${}_2$Si${}_2$ measured with planar microwave resonators and in-situ rotation
• Temperature and magnetic field dependent $g$-factors in electron spin resonance spectroscopy