标题： 非绝热跃迁于绝热面之间：超导原子点接触中的相位扩散 显示英文标题

标题： Nonadiabatic transitions between adiabatic surfaces: phase diffusion in superconducting atomic point contacts

摘要： 受电流偏置超导原子点接触实验的启发，研究了在强耗散存在下非绝热过渡到绝热表面的一般问题。 对于单通道器件，超电流由两个Andreev能级上的超导相位差的扩散运动决定。 这些表面仅在低至中等传输率的绝热极限下是解耦的，而对于高传输率，曲线交叉变得重要。 从全密度矩阵的一般主方程出发，在过阻尼极限下推导出绝热表面上布居数的近似时间演化方程，从中可以得到相关可观测量。 对于原子点接触的具体结果与常规理论无法解释的实验观测结果一致。 显示英文摘要

摘要： Motivated by experiments with current biased superconducting atomic point contacts the general problem of nonadiabatic transitions between adiabatic surfaces in presence of strong dissipation is studied. For a single channel device the supercurrent is determined by the diffusive motion of the superconducting phase difference on two Andreev levels. These surfaces are uncoupled only in the adiabatic limit of low to moderate transmissions, while for high transmissions curve crossings are important. Starting from a general master equation of the full density matrix an approximate time evolution equation for the populations on the adiabatic surfaces in the overdamped limit is derived from which the relevant observables can be obtained. Specific results for the case of atomic point contacts are in agreement with experimental observations that cannot be explained by conventional theory.