近日，英国诺丁汉大学的Ben Lang及其研究团队取得一项新进展。经过不懈努力，他们对约瑟夫森结激光器中的多体纠缠进行了研究。相关研究成果已于2024年12月16日在国际知名学术期刊《物理评论A》上发表。

该研究团队分析了一个约瑟夫森光子学模型系统中的纠缠现象，该系统中一个直流电压偏置的约瑟夫森结耦合了一系列腔模，并用微波光子填充它们。研究人员采用近似二次哈密顿量模型，研究了随着系统约瑟夫森能量的增加，各模式之间产生的高斯纠缠。

研究发现，系统中的模式分成了一系列区块，给定区块内的模式之间会产生双体纠缠。给定区块内模式之间的三体纠缠也普遍存在，但其受限于特定的约瑟夫森能量范围。

该系统无需交流激发，即可为生成多模微波纠缠提供一种替代途径，而多模微波纠缠是量子技术中的重要资源。

附：英文原文

Title: Multipartite entanglement in a Josephson junction laser

Author: Ben Lang, Andrew D. Armour

Issue&Volume: 2024/12/16

Abstract: We analyze the entanglement in a model Josephson photonics system in which a dc voltage-biased Josephson junction couples a collection of cavity modes and populates them with microwave photons. Using an approximate quadratic Hamiltonian model, we study the Gaussian entanglement that develops between the modes as the Josephson energy of the system is increased. We find that the modes in the system fall into a series of blocks, with bipartite entanglement generated between modes within a given block. Tripartite entanglement between modes within a given block is also widespread, though it is limited to certain ranges of the Josephson energy. The system could provide an alternative route to generating multimode microwave entanglement, an important resource in quantum technologies, without the need for ac excitation.

DOI: 10.1103/PhysRevA.110.062611

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.062611