论文标题
Pauli在具有自旋轨道控制的硅量子点中的封锁
Pauli Blockade in Silicon Quantum Dots with Spin-Orbit Control
论文作者
论文摘要
量子计算不仅依赖于量子位的准确测量值,不仅用于读取计算的输出,还用于执行误差校正。大多数提出的可伸缩硅体系结构都利用Pauli对三胞胎状态进行旋转转换。在最近的实验中,有些情况下,保利封锁仅在平行的旋转配置之间维持,而不是传统的三胞胎封锁读数,而$ | t_0 \ rangle $迅速放松到单线状态,并留下$ | t_+\+\ \ \ \ rangle $和$ | t _-- \ t_- \ rangle $ nate blockaded blockaded-我们呼吁partity partity parity parity parity parity parity parity parity parity parity parity parity parity parity parity parity parity。两种类型的封锁都可以在量子计算中用于读数,但是对于最大化的保真度和了解系统运行的方式至关重要。我们设计并执行了一个实验,在该实验中,可以通过研究$ | t_0 \ rangle $放松率的基础物理学来识别奇偶校验和单线读数之间的交叉读数。通过控制由旋转轨道耦合引起的点之间的Zeeman能量差,可以在四个数量级上调整速率,这又取决于施加的磁场的方向。我们建议一个理论模型,结合了电荷噪声和放松效应,以定量解释我们的结果。在分析和数值上研究该模型,我们确定了在大量点上始终如一地获得按需的单元 - 三角形或奇偶校验读数的策略。我们还讨论了如何使用奇偶校验读数来执行完整的两数数分状态断层扫描及其对大规模硅量子计算机中量子误差检测方案的影响。
Quantum computation relies on accurate measurements of qubits not only for reading the output of the calculation, but also to perform error correction. Most proposed scalable silicon architectures utilize Pauli blockade of triplet states for spin-to-charge conversion. In recent experiments, there have been instances when instead of conventional triplet blockade readout, Pauli blockade is sustained only between parallel spin configurations, with $|T_0\rangle$ relaxing quickly to the singlet state and leaving $|T_+\rangle$ and $|T_-\rangle$ states blockaded -- which we call \textit{parity readout}. Both types of blockade can be used for readout in quantum computing, but it is crucial to maximize the fidelity and understand in which regime the system operates. We devise and perform an experiment in which the crossover between parity and singlet-triplet readout can be identified by investigating the underlying physics of the $|T_0\rangle$ relaxation rate. This rate is tunable over four orders of magnitude by controlling the Zeeman energy difference between the dots induced by spin-orbit coupling, which in turn depends on the direction of the applied magnetic field. We suggest a theoretical model incorporating charge noise and relaxation effects that explains quantitatively our results. Investigating the model both analytically and numerically, we identify strategies to obtain on-demand either singlet-triplet or parity readout consistently across large arrays of dots. We also discuss how parity readout can be used to perform full two-qubit state tomography and its impact on quantum error detection schemes in large-scale silicon quantum computers.