发表机构
Ramakrishna Mission Vivekananda Educational and Research Institute; TCG CREST; Academy of Scientific and Innovative Research (AcSIR)（拉马克里希纳使命维韦卡南达教育研究所; TCG CREST; 科学与创新研究学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究探究有限时间量子奥托引擎中跨谱储库关联的热力学效应，将非对角储库谱作为控制该类量子热机的新资源，发现关联强度可调控输出功率等性能。
AI 中文摘要
我们研究了具有两能级工作介质的有限时间量子奥托引擎中，纵向-横向跨谱储库关联的热力学后果。每个储库通过激发-弛豫和退相位通道耦合，其涨落由厄米半正定谱密度矩阵表征，非对角元素编码了它们的交叉关联。在二阶时间无卷积框架内推导了有限时间等容动力学，且未预先施加马尔可夫极限，因此有限储库记忆效应可通过随时间变化的耗散项和储库诱导的相干项引入。随后将所得动力学重写为布洛赫矢量形式，以构建冲程分辨的循环动力学。在固定自谱密度的情况下，跨谱关联会改变工作介质的布居数和相干性，从而改变其热力学性能。关联强度的增加可提高输出功率，该增强效果由跨谱相位和特征频率尺度控制。这些关联还会重塑瞬态的循环间演化及向周期运行的趋近过程，而对于此处考虑的布居数守恒幺正冲程，极限循环效率保持为奥托值不变。这些结果确立了非对角储库谱作为控制有限时间量子热机的额外资源。
英文摘要
We investigate the thermodynamic consequences of longitudinal-transverse cross-spectral reservoir correlations in a finite-time quantum Otto engine with a two-level working medium. Each reservoir couples through excitation-relaxation and dephasing channels whose fluctuations are characterized by a Hermitian positive-semidefinite spectral-density matrix, with the off-diagonal elements encoding their cross correlations. The finite-time isochoric dynamics is derived within the second-order time-convolutionless framework, without imposing the Markov limit at the outset, so that finite reservoir-memory effects can enter through time-dependent dissipative and reservoir-induced coherent contributions. The resulting dynamics is then recast in Bloch-vector form to construct the stroke-resolved cycle dynamics. At fixed auto-spectral densities, cross-spectral correlations modify the populations and coherences of the working medium and thereby its thermodynamic performance. Increasing the correlation strength can enhance the output power, with the enhancement controlled by the cross-spectral phase and characteristic frequency scale. The correlations also reshape the transient cycle-to-cycle evolution and the approach to periodic operation, while the limit-cycle efficiency remains fixed at the Otto value for the population-preserving unitary strokes considered here. These results establish off-diagonal reservoir spectra as an additional resource for controlling finite-time quantum thermal machines.
Comments26 pages, 7 figures
