论文标题
使用量子最佳控制
Qudit entanglers using quantum optimal control
论文作者
论文摘要
我们研究了使用量子最佳控制中的两种技术研究两量纠缠量子逻辑门的产生。我们利用了连续的,地位代数控制和数字,外分组控制。在这两种情况下,关键是访问时间依赖的哈密顿量,该汉密尔顿人可以在SU组中产生任意的单一矩阵($ d^2 $)。我们发现有效的协议来创建高保真纠缠的门。作为对我们理论的测试,我们研究了在碱土原子的核自旋中牢固地编码的Qudits案例,并用磁场和光场操纵,并由众所周知的Rydberg封锁引起了纠缠的相互作用。 We applied this in a case study based on a $d=10$ dimensional qudit encoded in the $I=9/2$ nuclear spin in $^{87}$Sr, controlled through a combination of nuclear spin-resonance, a tensor AC-Stark shift, and Rydberg dressing, which allows us to generate an arbitrary symmetric entangling two-qudit gate such as CPhase.我们的技术可用于实现核旋转中编码的任何$ 2 \ le d \ le10 $的纠缠大门。 We also studied how decoherence due to the finite lifetime of the Rydberg states affects the creation of the CPhase gate and found, through numerical optimization, a fidelity of $0.9985$, $0.9980$, $0.9942$, and $0.9800$ for $d=2$, $d=3$, $d=5$, and $d=7$ respectively.这提供了一个强大的平台,可以探索Qudits量子信息处理的各种应用,包括使用Qudits,量子模拟,通用量子计算和量子误差校正的计量学增强。
We study the generation of two-qudit entangling quantum logic gates using two techniques in quantum optimal control. We take advantage of both continuous, Lie-algebraic control and digital, Lie-group control. In both cases, the key is access to a time-dependent Hamiltonian which can generate an arbitrary unitary matrix in the group SU($d^2$). We find efficient protocols for creating high-fidelity entangling gates. As a test of our theory, we study the case of qudits robustly encoded in nuclear spins of alkaline earth atoms and manipulated with magnetic and optical fields, with entangling interactions arising from the well-known Rydberg blockade. We applied this in a case study based on a $d=10$ dimensional qudit encoded in the $I=9/2$ nuclear spin in $^{87}$Sr, controlled through a combination of nuclear spin-resonance, a tensor AC-Stark shift, and Rydberg dressing, which allows us to generate an arbitrary symmetric entangling two-qudit gate such as CPhase. Our techniques can be used to implement qudit entangling gates for any $2\le d \le10$ encoded in the nuclear spin. We also studied how decoherence due to the finite lifetime of the Rydberg states affects the creation of the CPhase gate and found, through numerical optimization, a fidelity of $0.9985$, $0.9980$, $0.9942$, and $0.9800$ for $d=2$, $d=3$, $d=5$, and $d=7$ respectively. This provides a powerful platform to explore the various applications of quantum information processing of qudits including metrological enhancement with qudits, quantum simulation, universal quantum computation, and quantum error correction.