Towards a global phase diagram of Ce-based dipolar-octupolar pyrochlore magnets under magnetic fields

TL;DR

This paper explores the phase behavior of Ce-based dipolar-octupolar pyrochlore magnets under various magnetic field directions, using theoretical models and simulations to identify signatures of quantum spin ice states.

Contribution

It introduces a comprehensive analysis of magnetic field effects on dipolar-octupolar pyrochlores, revealing unique experimental signatures and phase diagram features.

Findings

Distinct phase diagrams for different field directions

Unique signatures in structure factors and magnetostriction

Evidence supporting $$-flux quantum spin ice states

Abstract

Recent experiments have established a strong case for Ce$_2$(Zr, Sn, Hf)$_2$O$_7$ to host $\pi$-flux quantum spin ice (QSI). However, an irrefutable conclusion still requires strong, multifaceted evidence. In dipolar-octupolar (DO) compounds, external magnetic fields only strongly couple with the dipolar component $\tau_z$ along its local z-axis in contrast to octupolar components $\tau^{x,y}$. This gives rise to the unique ways magnetic fields interact with the system and, in turn, provides us with a variety of tuning knobs to generate comprehensive experimental results. In this work, we focus on magnetic fields along the (110), (111), and (001) directions and present a plethora of remarkable experimental signatures to probe the underlying physics of $\pi$-flux QSI using gauge mean field theory (GMFT) and Monte Carlo simulations. In particular, we present unique signatures in magnetic field-dependent phase diagrams, equal-time and dynamical structure factors, and magnetostriction.