Quantum battery with non-Hermitian charging

TL;DR

This paper introduces a quantum battery design using non-Hermitian Hamiltonians as chargers, demonstrating enhanced power output and performance stability across system sizes and temperatures, compared to Hermitian counterparts.

Contribution

It presents a novel quantum battery model with non-Hermitian charging Hamiltonians, showing improved energy transfer and robustness over traditional Hermitian systems.

Findings

Non-Hermitian Hamiltonians enhance charging power.

Performance gains persist with increasing system size.

Advantages remain at finite temperatures.

Abstract

We propose a design of a quantum battery exploiting the non-Hermitian Hamiltonian as a charger. In particular, starting with the ground or the thermal state of the interacting (non-interacting) Hamiltonian as the battery, the charging of the battery is performed via parity-time (PT)- and rotational-time (RT)-symmetric Hamiltonian to store energy. We report that such a quenching with a non-Hermitian Hamiltonian leads to an enhanced power output compared to a battery with a Hermitian charger. We identify the region in the parameter space which provides the gain in performance. We also demonstrate that the improvements persist with the increase of system size for batteries with both PT- and RT-symmetric chargers. In the PT-symmetric case, although the anisotropy of the XY model does not help in the performance, we show that the XXZ model as a battery with a non-Hermitian charger performs better than that of the XX model having certain interaction strengths. We also exhibit that the advantage of non-Hermiticity remains valid even at finite temperatures in the initial states.