标题： 通过非均匀磁场增加量子速度极限 显示英文标题

标题： Increasing quantum speed limit via non-uniform magnetic field

摘要： 量子速限（QSL）定义了量子系统在状态之间演化的理论上限。 它对量子信息处理的速率施加了一个基本约束。 对于处于均匀磁场中的相对论性自旋电子，QSL随着磁场强度增加直到大约$10^{15}$高斯，然后在饱和量子速限（SQSL）0.2407c处趋于饱和，其中c是光速。 我们表明，通过使用变化的磁场，可以超越这一限制，实现高达0.4-0.6c的SQSL。 为了实现这一量子现象，我们求解了在空间变化磁场中相对论电子的演化方程，并发现各种电子态的能量变得不简并，与恒定磁场的情况相反。 这种能量的重新分布是实现更高QSL和因此更高信息处理速度的关键因素。 我们进一步探讨了QSL如何作为相对论和非相对论量子动力学之间的桥梁，通过Bremermann-Bekenstein界限提供见解，这是一个限制信息产生最大速率的量。 我们还提出了一种实用的实验设置来实现这些进展。 这些结果在推动量子计算、热力学和计量学等领域具有巨大的潜力。 显示英文摘要

摘要： Quantum speed limit (QSL) defines the theoretical upper bound on how fast a quantum system can evolve between states. It imposes a fundamental constraint on the rate of quantum information processing. For a relativistic spin-up electron in a uniform magnetic field, QSL increased with the magnetic field strength till around $10^{15}$ Gauss, before saturating at a saturated QSL (SQSL) of 0.2407c, where c is the speed of light. We show that by using variable magnetic fields, it is possible to surpass this limit, achieving SQSL upto 0.4-0.6c. To attain this quantum phenomenon, we solve the evolution equation of relativistic electron in spatially varying magnetic fields and find that the energies of various electron states become non-degenerate as opposed to the constant magnetic field case. This redistribution of energy is the key ingredient to accomplish higher QSL and, thus, a high information processing speed. We further explore how QSL can serve as a bridge between relativistic and non-relativistic quantum dynamics, providing insights via the Bremermann-Bekenstein bound, a quantity which constrains the maximal rate of information production. We also propose a practical experimental setup to realize these advancements. These results hold immense potential for propelling fields of quantum computation, thermodynamics and metrology.