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

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 quantum speed (QS) on spin of electron and find that it is higher for spin-down electron for ground level based transition 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.

Quantum Correlations and Speed Limit of Central Spin Systems

“…[38] QSL time for the evolution between arbitrary states in open quantum systems finds many potential applications [39][40][41][42] in the field of quantum information and computation and is an active research topic. [43][44][45] In general, comprehending the subtlety of the environment's impact on the quantum system is a non-trivial task. In this work, we discuss the central spin system, [46,47] both single as well as double spin systems, [48,49] interacting with spin bath(s) and investigate the corresponding evolution under various conditions.…”

“…[ 38 ] QSL time for the evolution between arbitrary states in open quantum systems finds many potential applications [ 39–42 ] in the field of quantum information and computation and is an active research topic. [ 43–45 ]…”

Quantum dynamical speedup for correlated initial states

“…In recent years, due to the fact that it is difficult to access an initial pure state in practical scenarios, studying the QSL for mixed initial states has been the subject of some works [20,21]. In addition to providing different bounds, some works have been done on the issue of QSL, such as the dependence of QSL on the initial state [22], and many other works [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

Quantum dynamical speedup for correlated initial states

“…In recent years, due to the fact that it is difficult to access an initial pure state in practical scenarios, studying the QSL for mixed initial states has been the subject of some works ( [30,31]). In addition to providing different bounds, some works have been done on the issue of QSL, such as the dependence of QSL on the initial state [32], and many other works [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51].…”