Uniaxial stress tuning of geometrical frustration in a Kondo lattice

TL;DR

This study demonstrates how uniaxial stress along the a-direction in CeRhSn suppresses quantum criticality and induces complex magnetic phases, revealing the role of geometrical frustration in Kondo lattice behavior.

Contribution

It provides the first detailed experimental investigation of how uniaxial stress influences geometrical frustration and quantum criticality in a Kondo lattice system.

Findings

Uniaxial stress suppresses quantum criticality in CeRhSn.

A complex magnetic phase diagram emerges under stress.

Geometrical frustration is released by in-plane stress, altering magnetic behavior.

Abstract

Hexagonal CeRhSn with paramagnetic $4f$ moments on a distorted Kagome lattice displays zero-field quantum critical behavior related to geometrical frustration. We report high-resolution thermal expansion and magnetostriction measurements under multiextreme conditions such as uniaxial stress up to 200 MPa, temperatures down to 0.1 K and magnetic fields up to 10 T. Under uniaxial stress along the $a$-direction, quantum criticality disappears and a complex magnetic phase diagram arises with a sequence of phases below 1.2 K and fields between 0 and 3 T ($\parallel a$). Since the Kondo coupling increases with stress, which alone would stabilize paramagnetic behavior in CeRhSn, the observed order arises from the release of geometrical frustration by in-plane stress.