Universal holonomic quantum gates over geometric spin qubits with polarised microwaves
Universal holonomic quantum gates over geometric spin qubits with polarised microwaves
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DOI：
10.1038/s41467-018-05664-w
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发表时间：
2018-08-13
影响因子：
16.6
通讯作者：
Kosaka, Hideo
中科院分区：
文献类型：
--
作者：
Nagata, Kodai;Kuramitani, Kouyou;Kosaka, Hideo
微波在弹性散射后与相互作用的电子自旋共享一个非直观的相位，称为几何相位。几何位相通常被认为是一个整体位相，它允许对理想的逻辑量子比特进行普适的完整选通，我们称之为几何自旋量子比特，定义在三重态自旋量子比特的简并子空间中。我们在实验上演示了电子或氮核上的几何自旋量子比特上的非绝热和非阿贝尔完整量子门。我们在室温下，用偏振微波在零磁场下操纵了金刚石中氮空位中心的几何相。我们还通过操纵电子-核纠缠演示了一个两量子比特的完整门，从而展示了普适性。通用完整门允许快速和容错操作，以实现通用量子计算机和安全通信网络之间的量子中继器接口。
A microwave shares a nonintuitive phase called the geometric phase with an interacting electron spin after an elastic scattering. The geometric phase, generally discarded as a global phase, allows universal holonomic gating of an ideal logical qubit, which we call a geometric spin qubit, defined in the degenerate subspace of the triplet spin qutrit. We here experimentally demonstrate nonadiabatic and non-abelian holonomic quantum gates over the geometric spin qubit on an electron or nitrogen nucleus. We manipulate purely the geometric phase with a polarised microwave in a nitrogen-vacancy centre in diamond under a zero-magnetic field at room temperature. We also demonstrate a two-qubit holonomic gate to show universality by manipulating the electron-nucleus entanglement. The universal holonomic gates enable fast and fault-tolerant manipulation for realising quantum repeaters interfacing between universal quantum computers and secure communication networks.