论文标题
量子点中腔诱导的交换耦合测量的提案
Proposal for a cavity-induced measurement of the exchange coupling in quantum dots
论文作者
论文摘要
在自旋量子阵列中，可以利用交换耦合来实现两倍的门，并实现沿着自旋总线的中间量程量子连接性。在这项工作中，我们提出了一个方案，以表征相邻量子点中电子之间的交换耦合。从理论上讲，我们研究了微波谐振器与两个电子占用的三重量子点（TQD）的传播。我们假设右量子点（QD）总是被一个电子占据，而第二个电子可以在左侧和中心QD之间隧道。如果两个电子在相邻点中，它们通过交换耦合相互作用。通过分析计算，我们表明谐振器的传输曲线直接揭示了两个电子之间的交换耦合强度的值。从扰动理论到二阶，我们得出结论，在存在磁梯度的情况下仍然可以识别交换。与点间隧道耦合相当的山谷分裂将导致进一步修改也取决于山谷相的腔传输倾角。
In spin qubit arrays the exchange coupling can be harnessed to implement two-qubit gates and to realize intermediate-range qubit connectivity along a spin bus. In this work, we propose a scheme to characterize the exchange coupling between electrons in adjacent quantum dots. We investigate theoretically the transmission of a microwave resonator coupled to a triple quantum dot (TQD) occupied by two electrons. We assume that the right quantum dot (QD) is always occupied by one electron while the second electron can tunnel between the left and center QD. If the two electrons are in adjacent dots they interact via the exchange coupling. By means of analytical calculations we show that the transmission profile of the resonator directly reveals the value of the exchange coupling strength between two electrons. From perturbation theory up to second order we conclude that the exchange can still be identified in the presence of magnetic gradients. A valley splitting comparable to the inter-dot tunnel coupling will lead to further modifications of the cavity transmission dips that also depend on the valley phases.
