论文标题
分散腔介导的驱动点核核自旋之间的量子门
Dispersive cavity-mediated quantum gate between driven dot-donor nuclear spins
论文作者
论文摘要
核旋转表现出异常漫长的连贯性时间，但是在控制核自旋量子方面，与环境的良好隔离是一个挑战。一个特殊的困难，不仅是核自旋量子，是在遥远量子位之间实现了两倍的大门。最近，已经报道了电子自旋和微波谐振光子光子之间的强耦合以及微波谐振器介导的谐振和色散状态之间的两个电子旋转之间的耦合，因此，似乎可以触及微波谐振器介导的电子旋转两个Qubit两个Qubit两个Qubit两个Qubit。受这些发现的启发，我们从理论上研究了微波谐振器与由栅极定义的SI QD和侧向移位的$^{31} $ P磷供体原子组成的混合量子点插件（QDD）系统的相互作用。我们发现，驱动QDD系统可以补偿MHz制度中的供体核自旋分裂与GHz状态中典型的超导谐振频率之间的频率不匹配，还可以实现有效的核自旋旋转耦合。虽然我们希望这种耦合会很弱，但我们预测，将两个遥远的QDD系统的核旋转偶联到微波炉谐振器允许实现一个谐振器介导的核自旋旋转两倍$ \ sqrt {i \ mathrm {swap}} $ GATE与Gate Fidelity接近90 $ $ $ $ $ $ $ $ $ $ $。
Nuclear spins show exceptionally long coherence times but the underlying good isolation from their environment is a challenge when it comes to controlling nuclear spin qubits. A particular difficulty, not only for nuclear spin qubits, is the realization of two-qubit gates between distant qubits. Recently, strong coupling between an electron spin and microwave resonator photons as well as a microwave resonator mediated coupling between two electron spins both in the resonant and the dispersive regime have been reported and, thus, a microwave resonator mediated electron spin two qubit gate seems to be in reach. Inspired by these findings, we theoretically investigate the interaction of a microwave resonator with a hybrid quantum dot-donor (QDD) system consisting of a gate defined Si QD and a laterally displaced $^{31}$P phosphorous donor atom implanted in the Si host material. We find that driving the QDD system allows to compensate the frequency mismatch between the donor nuclear spin splitting in the MHz regime and typical superconducting resonator frequencies in the GHz regime, and also enables an effective nuclear spin-photon coupling. While we expect this coupling to be weak, we predict that coupling the nuclear spins of two distant QDD systems dispersively to the microwave resonator allows the implementation of a resonator mediated nuclear spin two-qubit $\sqrt{i\mathrm{SWAP}}$ gate with a gate fidelity approaching $90\%$.
