# Controlling decoherence via $\mathcal{PT}$-symmetric non-Hermitian open quantum systems

## TL;DR

This paper explores how non-Hermitian, $ ext{PT}$-symmetric baths influence quantum decoherence and entanglement, demonstrating that proper tuning can completely suppress decoherence in two-level systems.

## Contribution

It introduces a non-Hermitian Bosonic bath model and shows how adjusting non-Hermiticity parameters can control and eliminate decoherence in quantum systems.

## Key findings

- Decoherence can be fully eliminated with appropriate parameter choices.
- Non-Hermiticity can have both positive and negative effects on coherence.
- The bath influences entanglement dynamics when acting on a single spin.

## Abstract

We have studied the effect of a non-Hermitian Bosonic bath on the dynamics of a two-level spin system. The non-Hermitian Hamiltonian of the bath is chosen such that it converges to the harmonic oscillator Hamiltonian when the non-Hermiticity is switched off. We calculate the dynamics of the spin system and found that the non-Hermiticity can have positive as well as negative effects on the coherence of the system. However, the decoherence can be completely eliminated by choosing the non-Hermiticity parameter and the phase of the system bath interaction appropriately. We have also studied the effect of this bath on the entanglement of a two-spin system when the bath is acting only on one spin.