Entanglement Dynamics with a Stochastic Non-Hermitian Hamiltonian away from Exceptional Points

TL;DR

This paper investigates entanglement dynamics in two coupled qubits with stochastic non-Hermitian Hamiltonians away from exceptional points, revealing noise-resilient, rapid entanglement generation scalable to multiple qubits.

Contribution

It demonstrates that classical noise does not hinder, and can even enhance, efficient entanglement generation in non-Hermitian systems away from exceptional points.

Findings

Entanglement can be generated rapidly even with environmental noise.

The entanglement timescale is independent of the number of qubits.

Efficient entanglement generation is achievable beyond EPs, with potential for scalable quantum processors.

Abstract

Although non-Hermitian dynamics near exceptional points (EPs) provide a route to accelerated entanglement generation, entanglement can also be generated far from EPs at comparable or even higher rates. However, the behavior of such entanglement in open systems remains largely unexplored, rendering it highly susceptible to environmental noise. Here, we study entanglement dynamics in two coupled qubits described by a non-Hermitian Hamiltonian, where the dissipative rates are subject to stochastic noise. We focus on the regime away from EPs. Our approach demonstrates that, even in the presence of classical noise, rich dynamical control can be achieved, enabling highly efficient entanglement generation with a timescale that is significantly shorter than that of both Hermitian systems and EP-based non-Hermitian protocols. Additionally, the timescale is independent of the number of qubits, highlighting favorable scalability for multipartite entanglement generation and facilitating integration into future photonic quantum processors.