近日，日本金泽大学的Koji Ishiwata及其研究团队取得一项新进展。经过不懈努力，他们对磁性拓扑绝缘体中的集体激发与轴子暗物质搜索进行了研究。相关研究成果已于2024年10月30日在国际知名学术期刊《高能物理杂志》上发表。

该团队研究了磁性拓扑绝缘体（TIs）中的集体激发及其对轴子探测的影响。在包含哈伯德项的三维拓扑绝缘体模型中，研究人员通过反铁磁和铁磁状态下的动态磁化率，构建了磁振子和振幅模式的有效作用量。

其中一种振幅模式被识别为“轴子”准粒子，并且它与电磁场的有效耦合比先前估计增强了约四个数量级，这可能会极大地改变利用磁性拓扑绝缘体中的“轴子”，进行轴子搜索的灵敏度。

附：英文原文

Title: Collective excitations in magnetic topological insulators and axion dark matter search

Author: Ishiwata, Koji, Nomura, Kentaro

Issue&Volume: 2024-10-30

Abstract: We investigate collective excitations in magnetic topological insulators (TIs) and their impact on axion detection. In the three-dimensional TI model with the Hubbard term, the effective action of magnons and amplitude modes is formulated by dynamical susceptibility under the antiferromagnetic and ferromagnetic states. One of the amplitude modes is identified as “axionic” quasi-particle and its effective coupling to the electromagnetic fields turns out to be enhanced by about four orders of magnitude larger than the previous estimate, which may drastically change the sensitivity of the axion search using “axion” in magnetic TIs.

DOI: 10.1007/JHEP10(2024)225

Source: https://link.springer.com/article/10.1007/JHEP10(2024)225