Dynamical spin-nematic order in a transverse field Ising chain with non-Hermitian Gamma interaction

TL;DR

This paper explores how non-Hermitian Gamma interactions induce dynamical spin-nematic order and complex phase transitions in a transverse field Ising chain, revealing new quantum phases and non-equilibrium behaviors.

Contribution

It demonstrates the emergence of dynamical spin-nematic order due to parity-time symmetry breaking in a non-Hermitian Ising model, a novel phenomenon in quantum spin chains.

Findings

Discovery of a gapless phase with long-range spin-nematic order

Identification of dynamical spin-nematic order induced by PT symmetry breaking

Proposed scheme for generating spin-nematic order in spin chains

Abstract

We investigate the effect of non-Hermitian Gamma interaction on the phase transitions and magnetic correlations for the transverse field Ising chain. We demonstrate that apart from the gapped ferromagnetic and paramagnetic phases, there is a gapless phase, where the system exhibits long-range spin-nematic order induced by parity-time symmetry breaking. Furthermore, we reveal that the parity-time symmetry breaking leads to the emergence of dynamical spin-nematic order, which also suggests a way of characterizing the spin-nematic phase diagram through non-equilibrium dynamics. Our findings show rich quantum phases stem from the competition among the Ising interaction, transverse field and non-Hermitian Gamma interaction, as well as providing a scheme for generating spin-nematic order in the spin chain.