能量相干性产生的可提取功与热力学第三定律
Ergotropy from energetic coherence and the third law of thermodynamics
- Universidad Nacional Autónoma de México（墨西哥国立自治大学）
- Università di Pavia（帕维亚大学）
- Farmingdale State College SUNY（法明代尔斯州立学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过复合系统-浴耦合产生稳态相干性，研究量子比特电池的可提取功，发现其来自相干性，低温下受第三定律限制，且多量子比特时相干性指数增长而可提取功线性增长。
AI中文摘要：
我们研究了由与热环境辅助量子比特（qubit）或振子（oscillator）簇的重复相互作用充电的量子比特电池的可提取功（ergotropy）和热力学势。这种相互作用通过复合系统-浴耦合产生能量基下的稳态相干性。一个编码浴量子统计的单一参数，对于任意簇大小，以闭合形式给出了相干性和可提取功。对于大簇，可提取功变得独立于浴统计，并且在最优耦合下，达到量子比特在浴温度下平衡内能的普适分数。由于充电态没有粒子数反转，所有可提取的功都来自相干性。可提取功在低温下是平坦的。我们将这一平台归因于第三定律，并表明可提取功与量子比特的平衡焓成正比，其斜率随热容消失。对于由多个量子比特组成的电池，相干性随量子比特数量指数增长，而可提取功线性增长，两者都保持其各自最大值的近乎恒定分数。充电态是零温度下具有有限熵的非平衡稳态，由切换碰撞相互作用的开关功维持。当平行耦合非零时，该成本非零，并且与可提取功不同，它依赖于浴统计。
英文摘要：
We study the ergotropy and the thermodynamic potentials of a qubit battery charged by repeated interactions with clusters of thermal ancillas, qubits or oscillators, through a composite system-bath coupling that generates steady-state coherence in the energy basis. A single parameter encoding the bath quantum statistics yields the coherence and ergotropy in closed form for any cluster size. For large clusters, the ergotropy becomes independent of the bath statistics and, at optimal couplings, reaches a universal fraction of the equilibrium internal energy of the qubit at the bath temperature. Since the charged state has no population inversion, all extractable work comes from coherence. The ergotropy is flat at low temperatures. We trace this plateau to the third law, and show that the ergotropy is proportional to the equilibrium enthalpy of the qubit, whose slope vanishes with the heat capacity. For a battery composed of multiple qubits, the coherence grows exponentially with the number of qubits while the ergotropy grows linearly, both remaining a nearly constant fraction of their respective maxima. The charged state is a non-equilibrium steady state with finite entropy at zero temperature, sustained by the work of switching the collisional interaction on and off. The cost is nonzero whenever the parallel coupling is nonzero, and, unlike the ergotropy, it depends on the bath statistics.
