Title: experimental realisation of multi-qubit gates using electron paramagnetic resonance.
Title: experimental realisation of multi-qubit gates using electron paramagnetic resonance.
复制标题
DOI：
10.1038/s41467-023-42169-7
复制
发表时间：
2023-11-02
影响因子：
16.6
通讯作者：
Winpenny, Richard E P
中科院分区：
文献类型：
--
作者：
Little, Edmund J;Mrozek, Jacob;Rogers, Ciaran J;Liu, Junjie;McInnes, Eric J L;Bowen, Alice M;Ardavan, Arzhang;Winpenny, Richard E P
量子信息处理有望彻底改变计算；人们发现量子算法能够比经典算法更有效地解决常见任务。要使物理系统成为可行的量子计算机，必须能够初始化其量子态，实现一组通用量子逻辑门（包括至少一个多量子位门），并对量子位态进行测量。分子电子自旋量子位 (MESQ) 已被提议满足这些标准，因为它们的自下而上合成应有助于根据需要调整性能以及多 MESQ 结构的可重复生产。在这里，我们探索如何在多 MESQ 系统上执行两个量子位纠缠门，以及如何通过量子态断层扫描读出状态。我们提出了使用多频脉冲电子顺磁共振（EPR）完成这两个过程的方法，并将其应用于由两个氮氧自旋中心组成的模型 MESQ 结构。我们的结果证实了方法原理，并揭示了在该系统上实现受控纠缠演示必须克服的实验障碍。分子电子自旋是有前途的量子位候选者，但量子门的物理实现具有挑战性。小等人。基于 NMR 量子计算协议，探索通过脉冲电子顺磁共振在硝基氧自旋中心之间实现两个量子位纠缠门。
Quantum information processing promises to revolutionise computing; quantum algorithms have been discovered that address common tasks significantly more efficiently than their classical counterparts. For a physical system to be a viable quantum computer it must be possible to initialise its quantum state, to realise a set of universal quantum logic gates, including at least one multi-qubit gate, and to make measurements of qubit states. Molecular Electron Spin Qubits (MESQs) have been proposed to fulfil these criteria, as their bottom-up synthesis should facilitate tuning properties as desired and the reproducible production of multi-MESQ structures. Here we explore how to perform a two-qubit entangling gate on a multi-MESQ system, and how to readout the state via quantum state tomography. We propose methods of accomplishing both procedures using multifrequency pulse Electron Paramagnetic Resonance (EPR) and apply them to a model MESQ structure consisting of two nitroxide spin centres. Our results confirm the methodological principles and shed light on the experimental hurdles which must be overcome to realise a demonstration of controlled entanglement on this system. Molecular electron spins are promising qubit candidates, however physical implementation of quantum gates is challenging. Little et al. explore the implementation of two-qubit entangling gates between nitroxide spin centres by pulsed electron paramagnetic resonance, building on NMR quantum computing protocols.