Vaporization of Kitaev spin liquids

TL;DR

This paper investigates the vaporization process of Kitaev spin liquids, revealing that in three-dimensional models, quantum spin liquids are separated from paramagnets by phase transitions, challenging previous assumptions about their thermodynamic behavior.

Contribution

It demonstrates that 3D Kitaev quantum spin liquids exhibit phase transitions at low temperatures, contrasting with the belief that they smoothly connect to paramagnets without singularities.

Findings

Quantum spin liquids in 3D are separated from paramagnets by phase transitions.

Both gapless and gapped phases are distinguished from high-temperature paramagnets.

Challenges the idea that absence of singularity implies a spin liquid.

Abstract

Quantum spin liquid is an exotic quantum state of matter in magnets. This state is a spin analogue of the liquid helium which does not solidify down to the lowest temperature due to strong quantum fluctuations. In conventional fluids, liquid and gas possess the same symmetry and adiabatically connect to each other by bypassing the critical end point. We find that the situation is qualitatively different in quantum spin liquids realizing in a three-dimensional Kitaev model; both gapless and gapped quantum spin liquid phases at low temperatures are always distinguished from the high-temperature paramagnet (spin gas) by a phase transition. The results challenge common belief that the absence of thermodynamic singularity down to the lowest temperature is a symptom of a quantum spin liquid.