Time scaling and quantum speed limit in non-Hermitian Hamiltonians

TL;DR

This paper introduces a time scaling method for non-Hermitian quantum systems that improves fidelity and preserves quantum speed limits without additional couplings, enhancing quantum protocol performance.

Contribution

The authors develop a novel time scaling technique for non-Hermitian Hamiltonians that boosts quantum fidelity and maintains optimal speed limits without extra couplings.

Findings

Significant enhancement of quantum fidelity in non-Hermitian systems.

Preservation of quantum speed limit with reduced damping.

Applicability to quantum state transfer in 2- and 3-level systems.

Abstract

We report on a time scaling technique to enhance the performances of quantum protocols in non-Hermitian systems. The considered time scaling involves no extra-couplings and yields a significant enhancement of the quantum fidelity for a comparable amount of resources. We discuss the application of this technique to quantum state transfers in 2 and 3-level open quantum systems. We derive the quantum speed limit in a system governed by a non-Hermitian Hamiltonian. Interestingly, we show that, with an appropriate driving, the time-scaling technique preserves the optimality of the quantum speed with respect to the quantum speed limit while reducing significantly the damping of the quantum state norm.