The phase diagram and vortex properties of PT-symmetric non-Hermitian two-component superfluid

TL;DR

This paper explores the phase diagram and vortex dynamics in a PT-symmetric non-Hermitian two-component superfluid model, revealing complex phase interactions and richer vortex behavior compared to Hermitian systems.

Contribution

It introduces a detailed analysis of the phase diagram and vortex properties in a non-Hermitian PT-symmetric model with two interacting scalar fields, highlighting novel dynamical features.

Findings

Identification of stable PT-symmetric and unstable PT-broken regions

Existence of classical vortex solutions in PT-symmetric phases

Richer vortex dynamics compared to Hermitian analogs

Abstract

We discuss the phase diagram and properties of global vortices in the non-Hermitian parity-time-symmetric relativistic model possessing two interacting scalar complex fields. The phase diagram contains stable PT-symmetric regions and unstable PT-broken regions, which intertwine nontrivially with the U(1)-symmetric and U(1)-broken phases, thus forming rich patterns in the space of parameters of the model. The notion of the PT-symmetry breaking is generalized to the interacting theory. At finite quartic couplings, the non-Hermitian model possesses classical vortex solutions in the PT-symmetric regions characterized by broken U(1) symmetry. In the long-range limit of two-component Bose-Einstein condensates, the vortices from different condensates experience mutual dissipative dynamics unless their cores overlap precisely. For comparison, we also consider a close Hermitian analog of the system and demonstrate that the non-Hermitian two-component model possesses much richer dynamics than its Hermitian counterpart.