AI 中文总结
该研究提出一种由库调控非平衡占据态驱动的约瑟夫森二极管机制，在双量子点结中实现，经Keldysh-Lindblad计算验证其对实际结的鲁棒性。
AI 中文摘要
我们提出一种约瑟夫森二极管机制，其非互易性并非源于传统的不对称安德烈夫谱，而是源于由附加库调控的载流态的非平衡占据。我们在双量子点结中实现了该机制，其中具有相位结构的非局域库充当量子芝诺选择器：快速耗散会冻结与跃迁算符L直接耦合的亮态，同时保留正交的暗安德烈夫通道，其超流与无损耗结的超流相当。在无穷大间隙极限下，稳态电流可分解为I_ss = I_A P_γ，因此即使安德烈夫电流I_A严格互易，仅P_γ的相位不对称性也能通过库调控产生约瑟夫森二极管效应。我们进一步表明，局域库仑排斥可通过暗对共振驱动系统趋近近理想二极管 regime。利用Keldysh-Lindblad计算，我们证明对于具有有限超导间隙和耗散的实际结，结果仍具有鲁棒性。
英文摘要
We propose a Josephson diode mechanism in which nonreciprocity arises not from a conventional asymmetric Andreev spectrum but from nonequilibrium occupation of the current-carrying states engineered by attached reservoirs. We realize this mechanism in a double-quantum-dot junction, where a phase-textured nonlocal reservoir acts as a quantum Zeno selector: rapid dissipation freezes out the bright state directly coupled to the jump operator $L$, while preserving an orthogonal dark Andreev channel whose supercurrent remains comparable to that of the lossless junction. In the infinite-gap limit, the steady-state current factorizes as $I_{\rm ss}=I_A P_γ$, so that even when the Andreev current $I_A$ is strictly reciprocal, the phase asymmetry of $P_γ$ alone can produce a Josephson diode effect through reservoir engineering. We further show that local Coulomb repulsion can drive the system toward a nearly ideal diode regime via a dark-pair resonance. Using Keldysh-Lindblad calculations, we demonstrate that our results remain robust for realistic junctions with a finite superconducting gap and dissipation.
Comments26 pages, 7 figures
