Observation of field-induced single-ion magnetic anisotropy in a multiorbital Kondo alloy $\mathrm{(Lu,Yb)}\mathrm{Rh}_{2}\mathrm{Zn}_{20}$

TL;DR

This study reveals field-induced single-ion magnetic anisotropy in a multiorbital Kondo alloy, demonstrating how the Kondo effect influences magnetic behavior and anisotropy at low temperatures and specific magnetic fields.

Contribution

It provides experimental evidence of field-induced magnetic anisotropy caused by the multiorbital Kondo effect in a Yb-based alloy, supported by susceptibility and resistivity measurements.

Findings

Single-ion anisotropic metamagnetic behavior observed at low temperatures.

Ground-state properties reproduced by SU(8) Kondo model with T_K = 60.9 K.

Magnetic anisotropy becomes evident above ~5 T, below the isotropic Kondo crossover field.

Abstract

We demonstrate field-induced single-ion magnetic anisotropy resulting from the multiorbital Kondo effect on the diluted ytterbium alloy $(\mathrm{Lu}_{1-x}\mathrm{Yb}_x)\mathrm{Rh}_2\mathrm{Zn}_{20}$. Single-ion anisotropic metamagnetic behavior is revealed in low-temperature regions where the local Fermi-liquid state is formed. Specific hea, low-field magnetic susceptibility, and resistivity indicate reproduction of the ground-state properties by the $\mathrm{SU}(N = 8)$ Kondo model with a relatively large $c$-$f$ hybridization of $T_{\mathrm{K}} = 60.9 \ \mathrm{K}$. Dynamical susceptibility measurements on $\mathrm{Yb}\mathrm{Rh}_2\mathrm{Zn}_{20}$ support realizing the multiorbital Kondo ground state in $(\mathrm{Lu}_{1-x}\mathrm{Yb}_x)\mathrm{Rh}_2\mathrm{Zn}_{20}$. The single-ion magnetic anisotropy becomes evident above $\sim5 \ \mathrm{T}$, which is lower than the isotropic Kondo crossover field of 22.7 T, verifying blurred low-lying crystal field states through the multiorbital Kondo effect.