制备协议依赖的量子Mpemba动力学：磁性可调石墨烯纳米环量子比特
Preparation-protocol-dependent quantum Mpemba dynamics in a magnetically tunable graphene nanotorus qubit
- Centro de Ciências e Tecnologia, Universidade Federal do Cariri（卡鲁鲁联邦大学科学与技术中心）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究揭示石墨烯纳米环量子比特中量子Mpemba效应的强度取决于初始态制备协议，裸Gibbs制备可产生强反常弛豫，而驱动稳态制备几乎抑制该效应，表明态制备可作为控制参数。
AI中文摘要：
我们研究了石墨烯纳米环量子比特中的量子Mpemba效应，并证明其强度强烈依赖于初始态的制备方式。我们比较了两种共享相同最终哈密顿量、热浴和马尔可夫Liouvillian算符的协议：裸Gibbs制备，其中相干驱动仅在最终淬火时开启；以及驱动稳态制备，其中初始态是驱动动力学的稳态。利用到最终稳态的距离和积分Mpemba参数，我们发现裸Gibbs制备存在广泛的强反常弛豫区域，$M_B$接近1，而驱动稳态协议几乎完全抑制了该效应。Liouvillian模式分析揭示了其机制：裸Gibbs协议通常导致慢活动扇区中的热态权重小于冷态，即$R_s<1$，而驱动稳态协议主要给出$R_s>1$。由于在相应参数点上两种协议的最终Liouvillian谱相同，这种对比源于制备依赖的模式权重，而非衰减率层级的变化。这些结果将态制备确立为弯曲石墨烯量子比特中反常量子弛豫的控制参数。
英文摘要：
We investigate the quantum Mpemba effect in a graphene nanotorus qubit and show that its strength depends strongly on how the initial state is prepared. We compare two protocols that share the same final Hamiltonian, thermal bath, and Markovian Liouvillian: bare Gibbs preparation, in which the coherent drive is switched on only at the final quench, and driven steady-state preparation, in which the initial states are stationary states of the driven dynamics. Using the distance to the final stationary state and an integrated Mpemba parameter, we find broad regions of strong anomalous relaxation for bare Gibbs preparation, with $M_B$ approaching unity, whereas the driven steady-state protocol almost completely suppresses the effect. A Liouvillian-mode analysis reveals the mechanism: the bare Gibbs protocol typically yields a smaller hot-state weight in the slow active sector than the cold state, $R_s<1$, while the driven steady-state protocol predominantly gives $R_s>1$. Since the final Liouvillian spectrum is identical for both protocols at corresponding parameter points, the contrast originates from preparation-dependent modal weights rather than from changes in the decay-rate hierarchy. These results identify state preparation as a control parameter for anomalous quantum relaxation in a curved graphene qubit.
