Exchange-only singlet-only spin qubit
Exchange-only singlet-only spin qubit
复制标题
仅交换单重态自旋量子位
DOI：
--
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
J. Danon
中科院分区：
文献类型：
--
作者：
A. Sala;J. Danon
我们提出了一个可行的和可扩展的量子点为基础的实施方案的单线态自旋量子比特，这是领先的顺序本质上不敏感的随机有效磁场设置的波动核自旋在主机半导体。因此，我们的提议消除了进一步改善高质量III-V族半导体（如GaAs）中自旋量子位的重要障碍。我们展示了如何只通过电气手段初始化，操纵和读出所产生的量子位，在某种程度上非常类似于三点交换自旋量子位。由于有效核场从量子比特哈密顿量中的内在消除，我们发现与类似的现有自旋量子比特相比，退相时间T_2 ^*$提高了几个数量级。
We propose a feasible and scalable quantum-dot-based implementation of a singlet-only spin qubit which is to leading order intrinsically insensitive to random effective magnetic fields set up by fluctuating nuclear spins in the host semiconductor. Our proposal thus removes an important obstacle for further improvement of spin qubits hosted in high-quality III-V semiconductors such as GaAs. We show how the resulting qubit could be initialized, manipulated, and read out by electrical means only, in a way very similar to a triple-dot exchange-only spin qubit. Due to the intrinsic elimination of the effective nuclear fields from the qubit Hamiltonian, we find an improvement of the dephasing time $T_2^*$ of several orders of magnitude as compared to similar existing spin qubits.