Non-uniform magnetic field as a booster for quantum speed limit: faster quantum information processing

TL;DR

This paper demonstrates that non-uniform magnetic fields can significantly increase the quantum speed limit, enabling faster quantum information processing, with dependencies on electron spin and relativistic effects, supported by analytical and experimental considerations.

Contribution

It introduces a method to enhance quantum speed limits using non-uniform magnetic fields and explores the relativistic effects on electron spin in this context.

Findings

Quantum speed limit increases with non-uniform magnetic fields.

Spin-down electrons exhibit higher QSL in the relativistic regime.

A critical magnetic field links non-relativistic and relativistic regimes.

Abstract

We probe the quantum speed limit (QSL) of an electron when it is trapped in a non-uniform magnetic field. We show that the QSL increases to a large value, but within the regime of causality, by choosing a proper variation in magnetic fields. We also probe the dependence of QSL on spin of electron and find that it is higher for spin-down electron in the relativistic regime. This can be useful in achieving a faster speed of transmission of quantum information. Further, we use the Bremermann--Bekenstein bound to find a critical magnetic field that bridges the gap between non-relativistic and relativistic treatments and relates to the stability of matter. An analytical framework is developed. We also provide a plausible experimental design to supplement our theory.