日本国家先进工业科学技术研究所Tsuyoshi Yamamoto团队研究了基于约瑟夫森参量振荡器的超导量子比特四体耦合器。相关论文于2025年6月10日发表在《物理评论A》杂志上。

研究组从理论上提出了一种基于约瑟夫森参量振荡器（JPOs）的超导量子比特四体耦合器电路。该四体相互作用耦合器有一个超导回路，类似于电容分流通量量子比特，其中外部磁通量设置为半通量量子。该耦合器电路是一种称为超导非线性不对称电感元件（SNAIL）的电路的特定设置，也是先前提出的JPO四体相互作用的推广。

研究组阐明了电路参数在四体相互作用中的作用，特别是表明，通过调整耦合器的电容或耦合器约瑟夫森结的面积比，可以显著增加该电路中的四体耦合常数。

附：英文原文

Title: Four-body coupler for superconducting qubits based on Josephson parametric oscillators

Author: Ryoji Miyazaki, Tsuyoshi Yamamoto

Issue&Volume: 2025/06/10

Abstract: We theoretically propose a circuit of the four-body coupler for superconducting qubits based on Josephson parametric oscillators (JPOs). Our coupler for the four-body interaction has a superconducting loop, similar to a capacitively shunted flux qubit, where an external magnetic flux set to half a flux quantum is threaded. This coupler circuit is a specific setup of the circuit called superconducting nonlinear asymmetric inductive elements (SNAIL) and also is a generalization of the previously proposed one for the four-body interaction of JPOs. We clarify roles of circuit parameters in the four-body interaction and, in particular, show that the four-body coupling constant in our circuit can be significantly increased by tuning capacitance of the coupler or the area ratio of the Josephson junctions of the coupler.

DOI: 10.1103/PhysRevA.111.062612

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.062612