论文标题
退化量子水平的单电子发射
Single-electron emission from degenerate quantum levels
论文作者
论文摘要
单电子源按需是一个有希望的全电子平台进行固态量子信息处理的必要条件。大多数实验实现的来源都使用这样一个事实，即只能从单一占据的量子水平中获取一个电子。在这里，我采取下一步，讨论从轨道变性的量子水平（例如在具有非平凡环拓扑的量子点）中产生的发射。我表明，退化为单电子和两电子发射提供了额外的灵活性。的确，略微提升堕落的小型Aharonov-Bohm通量是一种强大的工具，可以在较大范围内更改发射波包的相对宽度。在一个带有一个导线的环中，如果以适当的速率变化，则甚至从完全退化水平发出的电子也可以及时分开。在一个带有两个导线的环中，如果其中一个导线在其末端具有Fermi能量的结合状态，则可以将电子发射到不同的导线上。
Single-electron sources on-demand are requisite for a promising fully electronic platform for solid-state quantum information processing. Most of the experimentally realized sources use the fact that only one electron can be taken from a singly occupied quantum level. Here I take the next step and discuss emission from orbitally degenerate quantum levels that arise, for example, in quantum dots with a nontrivial ring topology. I show that degeneracy provides additional flexibility for single- and two-electron emission. Indeed, the small Aharonov-Bohm flux, which slightly lifts the degeneracy, is a powerful tool for changing the relative width of the emitted wave packets over a wide range. In a ring with one lead, even electrons emitted from completely degenerate levels can be separated in time if the driving potential changes at the appropriate rate. In a ring with two leads, electrons can be emitted to different leads if one of the leads has a bound state with Fermi energy at its end.
