Koppens F H L, Buizert C, Tielrooij K J, Vink I T, Nowack K C, Meunier T, Kouwenhoven L P, Vandersypen L M K
Kavli Institute of NanoScience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands.
Nature. 2006 Aug 17;442(7104):766-71. doi: 10.1038/nature05065.
The ability to control the quantum state of a single electron spin in a quantum dot is at the heart of recent developments towards a scalable spin-based quantum computer. In combination with the recently demonstrated controlled exchange gate between two neighbouring spins, driven coherent single spin rotations would permit universal quantum operations. Here, we report the experimental realization of single electron spin rotations in a double quantum dot. First, we apply a continuous-wave oscillating magnetic field, generated on-chip, and observe electron spin resonance in spin-dependent transport measurements through the two dots. Next, we coherently control the quantum state of the electron spin by applying short bursts of the oscillating magnetic field and observe about eight oscillations of the spin state (so-called Rabi oscillations) during a microsecond burst. These results demonstrate the feasibility of operating single-electron spins in a quantum dot as quantum bits.
控制量子点中单个电子自旋的量子态的能力是近期朝着可扩展的基于自旋的量子计算机发展的核心。结合最近展示的两个相邻自旋之间的受控交换门，驱动相干单自旋旋转将允许进行通用量子操作。在此，我们报告了在双量子点中实现单电子自旋旋转的实验。首先，我们施加一个在芯片上产生的连续波振荡磁场，并在通过两个量子点的自旋相关输运测量中观察电子自旋共振。接下来，我们通过施加振荡磁场的短脉冲来相干地控制电子自旋的量子态，并在微秒级脉冲期间观察到自旋态的大约八次振荡（所谓的拉比振荡）。这些结果证明了将量子点中的单电子自旋用作量子比特进行操作的可行性。
