Fluctuation-induced first order phase transitions in Kitaev-like $d^4$ honeycomb magnet

TL;DR

This study investigates a bosonic analog of the Kitaev honeycomb model, revealing that phase transitions between paramagnetic and ordered states are typically fluctuation-induced first order transitions, with implications for certain quantum magnets.

Contribution

The paper introduces a bosonic analog of the Kitaev model and demonstrates that phase boundaries are fluctuation-induced first order transitions through combined theoretical and numerical analysis.

Findings

Phase boundaries are fluctuation-induced first order transitions.

Results are relevant to Ru$^{4+}$- and Ir$^{5+}$-based honeycomb magnets.

Constructed phase diagram using Landau theory and quantum Monte Carlo.

Abstract

We study numerically a bosonic analog of the Kitaev honeycomb model, which is a minimal model for $4d^4/5d^4$ quantum magnets with honeycomb lattice geometry. We construct its phase diagram by a combination of Landau theory analysis and quantum Monte Carlo simulations. In particular, we show that the phase boundaries between the paramagnetic state and magnetically ordered states are generically fluctuation-induced first order phase transitions. Our results are potentially applicable to Ru$^{4+}$- and Ir$^{5+}$-based honeycomb magnets.