论文标题
交换和超级交换的相互作用在三重量子点中
Interplay of exchange and superexchange in triple quantum dots
论文作者
论文摘要
对半导体量子点的最新实验已经证明了利用大量量子点介导甲基互动相互作用并在遥远的旋转之间产生纠缠的能力。这为在较大的量子点网络中选择性耦合对远程旋转的可能机制打开了可能的机制。利用这一机会，需要更深入地了解如何控制这些系统中的superexchange相互作用。在这里，我们考虑了一个以线性和三角形几何形式排列的三点系统。我们使用配置交互计算来研究superexchange和最近的邻居交换的相互作用，因为中介点的位置，失调和电子数是不同的。我们表明，随着点接近线性配置，superexchange过程会强烈增强并增加净自旋旋转交换的范围。此外，我们表明交换相互作用的强度取决于调解人中电子的数量。我们的结果可以用作指南，以帮助进一步的实验努力，以扩展到更大的二维量子点阵列。
Recent experiments on semiconductor quantum dots have demonstrated the ability to utilize a large quantum dot to mediate superexchange interactions and generate entanglement between distant spins. This opens up a possible mechanism for selectively coupling pairs of remote spins in a larger network of quantum dots. Taking advantage of this opportunity requires a deeper understanding of how to control superexchange interactions in these systems. Here, we consider a triple-dot system arranged in linear and triangular geometries. We use configuration interaction calculations to investigate the interplay of superexchange and nearest-neighbor exchange interactions as the location, detuning, and electron number of the mediating dot are varied. We show that superexchange processes strongly enhance and increase the range of the net spin-spin exchange as the dots approach a linear configuration. Furthermore, we show that the strength of the exchange interaction depends sensitively on the number of electrons in the mediator. Our results can be used as a guide to assist further experimental efforts towards scaling up to larger, two-dimensional quantum dot arrays.
