Carter Samuel G, Badescu Stefan C, Bracker Allan S, Yakes Michael K, Tran Kha X, Grim Joel Q, Gammon Daniel
Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA.
Air Force Research Laboratory, Sensors Directorate, Wright Patterson Air Force Base, Ohio 45433, USA.
Phys Rev Lett. 2021 Mar 12;126(10):107401. doi: 10.1103/PhysRevLett.126.107401.
Optical spin rotations and cycling transitions for measurement are normally incompatible in quantum dots, presenting a fundamental problem for quantum information applications. Here we show that for a hole spin this problem can be addressed using a trion with one hole in an excited orbital, where strong spin-orbit interaction tilts the spin. Then, a particular trion triplet forms a double Λ system, even in a Faraday magnetic field, which we use to demonstrate fast hole spin initialization and coherent population trapping. The lowest trion transitions still strongly preserve spin, thus combining fast optical spin control with cycling transitions for spin readout.
在量子点中，用于测量的光学自旋旋转和循环跃迁通常是不兼容的，这给量子信息应用带来了一个基本问题。在这里，我们表明，对于空穴自旋，这个问题可以通过使用一个在激发轨道中有一个空穴的三重激子来解决，其中强自旋轨道相互作用会使自旋倾斜。然后，即使在法拉第磁场中，一个特定的三重激子三重态也会形成一个双Λ系统，我们用它来演示快速空穴自旋初始化和相干布居捕获。最低的三重激子跃迁仍然强烈地保持自旋，从而将快速光学自旋控制与用于自旋读出的循环跃迁相结合。
