非平衡相互作用双点系统中的量子纠缠和输运：简并的奇异作用
Quantum entanglement and transport in non-equilibrium interacting double-dot setup: The curious role of degeneracy
摘要：
研究了与电子浴相连的非平衡相互作用双点系统中的量子纠缠及其与输运的关系。在非相互作用制度的动力学性质进行了研究，使用精确的数值方法，而获得的稳定状态下的属性，著名的非平衡格林函数（NEGF）的方法。通过互信息和并发性，我们探讨了系统中的量子关联与流过量子点的电流之间的联系。据观察，点之间的纠缠度受到点能级的简并性或缺乏简并性的严重影响。在非简并情况下，当外加偏压超过某个临界值时，并发度急剧下降。相反，当点能级是简并的时，并发达到非常高的渐近值1/2。当相互作用被打开时，简并性被提升，并且在超过所施加的偏置的临界值时，并发性再次下降到零。最后观察到，如果两个浴中的化学势非常大（同时保持符号相同），只要点能级保持在非相互作用极限内简并，则可以使并发度几乎达到1.0的值。NEGF方法，蛮力数值和渐近相结合，以证实我们的研究结果。
英文摘要：
We study quantum entanglement and its relation to transport in a non-equilibrium interacting double dot system connected to electronic baths. The dynamical properties in the non-interacting regime are studied using an exact numerical approach whereas the steady state properties are obtained following the well-known non-equilibrium Green's function (NEGF) approach. By means of mutual information and concurrence we explore the connection between the quantum correlations in the system and the current flowing through the dots. It is observed that entanglement between the dots is heavily influenced by the degeneracy or the lack thereof, of the dot levels. In the non-degenerate case, the concurrence falls sharply when the applied bias crosses a certain critical value. In contrast when the dot energy levels are degenerate, the concurrence reaches a very high asymptotic value of 1/2. When interactions are switched on, the degeneracy is lifted, and once again concurrence falls to zero beyond a critical value of the applied bias. Lastly it is observed that the concurrence can be made to reach almost the value of 1.0 if the chemical potential in both baths is made very large (while keeping the sign the same) provided the dot levels are kept degenerate within the non-interacting limit. A combination of NEGF method, brute-force numerics and asymptotics are employed to corroborate our findings.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
