Stable dynamic helix state in the nonintegrable XXZ Heisenberg model

Abstract

We investigate the influence of external fields on the stability of spin helix states in an XXZ Heisenberg model. Exact diagonalization on a finite system shows that random transverse fields in the x and y directions drive the transition from integrability to nonintegrability. In such a system, the helix state can be regarded as a quantum scar. Simultaneously, the presence of uniform z field enables the helix state to better maintain its dynamical nature, allowing for a clearer understanding of its evolutionary behavior. However, the entanglement entropy reveals that irrespective of the presence of a uniform z field, as long as the system remains chaotic, the scar extent of the helix state shows no significant variation.