Entanglement Dynamics of two Non-Hermitian Qubits

TL;DR

This paper explores how entanglement evolves in a non-Hermitian two-qubit system, revealing distinct oscillatory and stable behaviors linked to $ ext{PT}$ symmetry, and suggests non-Hermiticity can help stabilize entanglement.

Contribution

It introduces a detailed analysis of entanglement dynamics in non-Hermitian qubits, highlighting the role of $ ext{PT}$ symmetry and decoherence effects, which is a novel approach.

Findings

Entanglement oscillates in low non-Hermiticity regimes.

Entanglement stabilizes at a fixed value in high non-Hermiticity regimes.

Non-Hermiticity can be exploited to stabilize quantum entanglement.

Abstract

The evolution of entanglement in a non-Hermitian quantum system may behave differently compared to its Hermitian counterpart. In this paper, we investigate the entanglement dynamics of two coupled and driven non-Hermitian qubits. Through calculating the concurrence of the system, we find that the evolution of the bipartite entanglement manifests two distinct patterns in the parameter space. In the low non-Hermiticity regime, the concurrence oscillates significantly, while in the opposite regime the same quantity would trend to a stable value. We attribute this phenomenon to parity-time ($ \mathcal{PT}$) symmetry phase transition. In addition, we have also studied the effect of decoherence on the entanglement dynamics. Our research provides a method to stabilize entanglement by exploiting non-Hermiticity.