Multiple metamagnetic transitions in helical antiferromagnet CeVGe$_3$

TL;DR

This study uncovers multiple magnetic phase transitions in CeVGe$_3$, including a quantum phase transition at 21.3 T, revealing complex magnetic behavior driven by exchange interactions and crystal symmetry.

Contribution

First detailed investigation of high-field magnetic phases and transitions in CeVGe$_3$, demonstrating multiple metamagnetic transitions and a quantum critical point.

Findings

Identification of incommensurate to commensurate AFM transition

Discovery of a novel high-field magnetic phase

Observation of a quantum phase transition at 21.3 T

Abstract

We report on neutron diffraction, magnetoresistance, magnetization, and magnetic torque measurements under high magnetic field in the helical antiferromagnet CeVGe$_3$. This compound exhibits Kondo lattice coherence and helical antiferromagnetic (AFM) ordering at ambient pressure, similar to the well-studied CeRhIn$_5$. Our measurements reveal that CeVGe$_3$ undergoes a magnetic transition from an incommensurate (ICM) AFM state to an up-up-down-down commensurate (CM) AFM structure, followed by a transition to a novel phase at higher fields. A quantum phase transition occurs around 21.3 T. This rich magnetic field phase diagram closely resembles that of CeRhIn$_5$. Furthermore, angle-dependent magnetoresistance measurements reveal that all transitions in CeVGe$_3$ occur from the field component along the $ab$ plane. These findings highlight the intricate interplay among exchange interactions, crystal field effects, ground state properties, and crystalline symmetries.