Simmons C B, Thalakulam Madhu, Rosemeyer B M, Van Bael B J, Sackmann E K, Savage D E, Lagally M G, Joynt R, Friesen Mark, Coppersmith S N, Eriksson M A
University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Nano Lett. 2009 Sep;9(9):3234-8. doi: 10.1021/nl9014974.
We report integrated charge sensing measurements on a Si/SiGe double quantum dot. The quantum dot is shown to be tunable from a single, large dot to a well-isolated double dot. Charge sensing measurements enable the extraction of the tunnel coupling t between the quantum dots as a function of the voltage on the top gates defining the device. Control of the voltage on a single such gate tunes the barrier separating the two dots. The measured tunnel coupling is an exponential function of the gate voltage. The ability to control t is an important step toward controlling spin qubits in silicon quantum dots.
我们报告了对一个硅/硅锗双量子点进行的集成电荷传感测量。结果表明，该量子点可从单个大尺寸量子点调谐为隔离良好的双量子点。电荷传感测量能够提取量子点之间的隧穿耦合t，它是定义该器件的顶部栅极上电压的函数。对单个此类栅极上电压的控制可调节分隔两个量子点的势垒。测得的隧穿耦合是栅极电压的指数函数。控制t的能力是朝着控制硅量子点中的自旋量子比特迈出的重要一步。
