近日，荷兰代尔夫特理工大学的Lieven M. K. Vandersypen及其研究团队取得一项新进展。他们实现了远距离自旋间空腔介导的iSWAP振荡。相关研究成果已于2024年12月9日在国际知名学术期刊《自然—物理学》上发表。

量子粒子之间的直接相互作用自然地随着距离的增加而减弱。然而，未来的量子计算架构很可能需要跨越，一系列长度尺度的量子比特之间的相互作用机制。

在这项工作中，研究人员利用超导谐振器实现了两个相隔250微米的，半导体自旋量子比特之间的相干相互作用。这一距离比该平台常用的直接相互作用机制大了几个数量级。研究人员使系统工作在一种模式下，即通过虚光子实现谐振器介导的自旋-自旋耦合。

研究人员报道了两个自旋粒子数以可控频率进行的反相振荡。这些观测结果与自旋量子比特的iSWAP振荡相一致，并表明在10纳秒内可能实现纠缠操作。这些结果为芯片上自旋量子比特模块的可扩展网络带来了希望。

附：英文原文

Title: Cavity-mediated iSWAP oscillations between distant spins

Author: Dijkema, Jurgen, Xue, Xiao, Harvey-Collard, Patrick, Rimbach-Russ, Maximilian, de Snoo, Sander L., Zheng, Guoji, Sammak, Amir, Scappucci, Giordano, Vandersypen, Lieven M. K.

Issue&Volume: 2024-12-09

Abstract: Direct interactions between quantum particles naturally fall off with distance. However, future quantum computing architectures are likely to require interaction mechanisms between qubits across a range of length scales. In this work, we demonstrate a coherent interaction between two semiconductor spin qubits 250μm apart using a superconducting resonator. This separation is several orders of magnitude larger than for the commonly used direct interaction mechanisms in this platform. We operate the system in a regime in which the resonator mediates a spin–spin coupling through virtual photons. We report the anti-phase oscillations of the populations of the two spins with controllable frequency. The observations are consistent with iSWAP oscillations of the spin qubits, and suggest that entangling operations are possible in 10ns. These results hold promise for scalable networks of spin qubit modules on a chip.

DOI: 10.1038/s41567-024-02694-8

Source: https://www.nature.com/articles/s41567-024-02694-8