Particle-hole symmetry breaking in a spin-dimer system TlCuCl$_3$ observed at 100 T

TL;DR

This study investigates the magnetization process of TlCuCl₃ up to 100 T, revealing particle-hole symmetry breaking caused by strong inter-dimer interactions, supported by experimental data and theoretical simulations.

Contribution

It provides the first experimental observation of particle-hole symmetry breaking in TlCuCl₃ at high magnetic fields and explains it through quantum Monte Carlo and bond-operator theories.

Findings

Particle-hole symmetry is broken in TlCuCl₃.

The upper critical field $H_{c2}$ is 86.1 T at 2 K.

Strong inter-dimer interactions cause symmetry breaking.

Abstract

The entire magnetization process of TlCuCl$_3$ has been experimentally investigated up to 100 T employing the single-turn technique. The upper critical field $H_{c2}$ is observed to be 86.1 T at 2 K. A convex slope of the $M$-$H$ curve between the lower and upper critical fields ($H_{c1}$ and $H_{c2}$) is clearly observed, which indicates that a particle-hole symmetry is broken in TlCuCl$_3$. By quantum Monte Carlo simulation and the bond-operator theory method, we find that the particle-hole symmetry breaking results from strong inter-dimer interactions.