During the last 20 years, the celebrated Jarzynski equality was established for various nonequilibrium systems, connecting the nonequilibrium work and free energy change between equilibriums. In the classical regime, we find that the nonequilibrium free energy change is independent of magnetism, as the Lorentz force does not conduct work. In contrast, the free energy change can be amplified by adding a magnetic field to driven quantum systems. Taking a recent experimental system as an example, the predicted amplification becomes 3-fold when adding a 10-tesla magnetic field under temperature 316 nanoKelvin. We further uncover the mechanism by examining the driving process. Through extending the path integral approach for quantum thermodynamics, we obtain a generalized free energy equality for both closed and open quantum systems. The equality reveals a decomposition on the source of the free energy change: one is the quantum work functional, and the other emerges from the magnetic flux passing through a closed loop of propagators. The result suggests a distinct quantum effect of magnetic flux and supports to extract additional free energy from the magnetic field. 

个人介绍：汤迎，北京师范大学珠海校区复杂系统国际科学中心的副研究员。上海交通大学物理系博士，加州大学洛杉矶分校定量和计算生物科学研究所博士后。研究领域为非平衡态系统的随机动力学、统计物理、生物物理、机器学习。近期主要科研成果有：利用机器学习发展了时间序列动力学互信息的计算框架；发现非平衡系统中一个新的量子效应：磁场不做功，却仍能增大自由能；建立了理解细胞坏死机制、细胞状态转换的数学模型和定量分析方法。研究发表在Nat.Commun.，Commun.Phys.，Phys.Rev.E，Nature，Nat.Methods，Mol.Sys.Biol.等，总引用1700余次，曾获加州大学洛杉矶分校Collaboratory Fellowship Award。 

个人网页：https://yingtangwebsite.netlify.app/ 

邀请人：周海军