Conditional rotation of two strongly coupled semiconductor charge qubits.
Conditional rotation of two strongly coupled semiconductor charge qubits.
复制标题
两个强耦合半导体电荷量子位的条件旋转
DOI：
10.1038/ncomms8681
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发表时间：
2015-07-17
影响因子：
16.6
通讯作者：
Guo GP
中科院分区：
文献类型：
--
作者：
Li HO;Cao G;Yu GD;Xiao M;Guo GC;Jiang HW;Guo GP
通用多量子位门可以由一组通用单量子位门和任意一种纠缠的双量子位门（如受控非门）来实现。对于半导体量子点量子比特，双量子比特门操作迄今为止仅在单个电子自旋量子点系统中得到证明。在这里，我们展示了两个电容耦合电荷量子位的条件旋转，每个量子位由一个限制在GaAs/AlGaAs双量子点中的电子组成。由于量子比特间耦合强度强，可以实现时钟速度高达6 GHz的门操作。控制非操作的真值表测量显示出与基于自旋的双量子位门相当的保真度，尽管相位相干性没有明确测量。我们的研究结果表明，半导体电荷量子位具有相当大的可扩展量子计算潜力，并可能刺激在其他设备中使用远程库仑相互作用进行相干量子控制。量子信息处理需要能够在多个量子位上运行的门。在这里，作者展示了在半导体双量子点中包含电子的两个耦合电荷量子比特上的受控非门操作。
Universal multiple-qubit gates can be implemented by a set of universal single-qubit gates and any one kind of entangling two-qubit gate, such as a controlled-NOT gate. For semiconductor quantum dot qubits, two-qubit gate operations have so far only been demonstrated in individual electron spin-based quantum dot systems. Here we demonstrate the conditional rotation of two capacitively coupled charge qubits, each consisting of an electron confined in a GaAs/AlGaAs double quantum dot. Owing to the strong inter-qubit coupling strength, gate operations with a clock speed up to 6 GHz have been realized. A truth table measurement for controlled-NOT operation shows comparable fidelities to that of spin-based two-qubit gates, although phase coherence is not explicitly measured. Our results suggest that semiconductor charge qubits have a considerable potential for scalable quantum computing and may stimulate the use of long-range Coulomb interaction for coherent quantum control in other devices. Quantum-information processing requires gates that can operate on multiple qubits. Here, the authors demonstrate a controlled-NOT gate operation on two coupled charge qubits comprising electrons confined in semiconductor double quantum dots.