Medina Ivan, Culhane Oisín, Binder Felix C, Landi Gabriel T, Goold John
Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, Brazil.
Trinity College Dublin, School of Physics, Dublin 2, Ireland.
Phys Rev Lett. 2025 Jun 6;134(22):220402. doi: 10.1103/PhysRevLett.134.220402.
Anomalous thermal relaxation is ubiquitous in nonequilibrium statistical mechanics. An emblematic example of this is the Mpemba effect, where an initially "hot" system cools faster than an initially "cooler" one. This effect has recently been studied in a variety of different classical and quantum settings. In this Letter, we find a novel signature of the Mpemba effect in the context of quantum batteries. We identify situations where batteries in higher charge states can discharge faster than less charged states. Specifically, we consider a quantum battery encoded in a single bosonic mode that is charged using unitary Gaussian operations. We show that the ergotropy, used here as a dynamical indicator of the energy stored in the battery, can be recast as a phase space relative entropy between the system's state and the unitarily connected passive state, at each time. Our formalism allows us to compute the ergotropy analytically under dissipative dynamics and allows us to understand the conditions which give rise to a Mpemba effect. We also find situations where two batteries charged to the same value using different operations can discharge at different rates.
反常热弛豫在非平衡统计力学中普遍存在。一个典型的例子就是姆潘巴效应，即一个初始“热”的系统比初始“冷”的系统冷却得更快。最近，这种效应已在各种不同的经典和量子环境中得到研究。在本信函中，我们在量子电池的背景下发现了姆潘巴效应的一种新特征。我们确定了高电荷态电池比低电荷态电池放电更快的情况。具体而言，我们考虑一个编码在单个玻色子模式中的量子电池，它通过幺正高斯操作进行充电。我们表明，这里用作电池中存储能量的动态指标的负熵，可以在每次时重新表述为系统状态与幺正连接的无源状态之间的相空间相对熵。我们的形式体系使我们能够在耗散动力学下解析计算负熵，并使我们能够理解产生姆潘巴效应的条件。我们还发现了使用不同操作充电到相同值的两个电池以不同速率放电的情况。
