Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2011 Jul 15;107(3):030506. doi: 10.1103/PhysRevLett.107.030506.
We report coherent operation of a singlet-triplet qubit controlled by the spatial arrangement of two confined electrons in an adjacent double quantum dot that is electrostatically coupled to the qubit. This four-dot system is the specific device geometry needed for two-qubit operations of a two-electron spin qubit. We extract the strength of the capacitive coupling between qubit and adjacent double quantum dot and show that the present geometry allows fast conditional gate operation, opening pathways toward implementation of a universal set of gates for singlet-triplet spin qubits.
我们报告了由相邻双量子点中两个受限电子的空间排列控制的单重态-三重态量子位的相干操作，该双量子点通过静电耦合与量子位相连。这种四量子点系统是双电子自旋量子位两量子比特操作所需的特定器件几何结构。我们提取了量子位和相邻双量子点之间电容耦合的强度，并表明目前的几何结构允许快速条件门操作，为单重态-三重态自旋量子位实现一组通用门开辟了道路。
