学术动态

报告人：管习文 研究员（中国科学院精密测量科学与技术创新研究院）

邀请人：李朝红 教授

时  间：2025年12月05日 10:00-11:30

地  点：深圳大学粤海校区光电所301报告厅

报告摘要：

The low-energy excitations of a one-dimensional (1D)  two-component repulsive ultracold atomic Fermi gas, i.e. Yang-Gaudin model,  decompose into two collective motions (carrying either only spin or charge degree of freedom), a hallmark of the unique 1D spin-charge separation phenomenon. However, the 1D interacting fermions with attractive interactions exhibit novel Bardeen-Cooper-Schrieffer pairing states strongly dependent on polarization, forming  the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)-pairing state or  a Luther-Emery liquid. The latter presents the fully paired state with an energy gap in spin excitations and gapless charge excitations.

This talk discusses these starkly different features of 1D interacting fermions via the Bethe ansatz and bosonization. Using a Feshbach resonance to access both repulsive and attractive interaction regions with 6Li atoms, we measured spin and charge dynamical structure factors via Bragg spectroscopy—and definitively observed spin-charge separation, consistent with nonlinear Luttinger liquids. Unlike repulsive interactions, we found spin waves propagate faster than charge density waves for the attractive interaction, revealing the pair-breaking nature of spin excitationsn and an inversion of the classic spin-charge separation.  Additionally, the RF spectra are consistent with an atom/molecule mixture stabilized by finite temperature and a spin-imbalance.

References:

He, Jiang, Lin, Hulet, Pu,  Guan, Phys. Rev. Lett.  125, 190401 (2020).

Senaratne, et. al., Pu, Guan, Hulet,  Science 376, 1305 (2022).

Kafle, et. al. Pu, Guan, Hulet, in preparation, 2025

Hai-Ying Cui, et al., and Xiwen Guan, in preparation, 2025

报告人简介：

管习文，研究员，中科院精密测量科学与技术创新研究院。 2003-2012年期间在澳大利亚国立大学物理与工程研究院任研究员、高级研究员，现为澳大利亚国立大学物理与工程研究院荣誉教授。他担任国家科技部重大科学研究计划项目的首席科学家和国家自然科学基金重点项目主持人，同时是美国哈佛大学、洛斯阿拉莫斯国家实验室等世界一流研究机构的高级访问学者, 清华大学高等研究院客座教授，香港中文大学杨振宁访问学人。担任《Journal of Physics A》的编委及IUPAP C18数学物理委员。管习文研究员长期从事冷原子多体系统、自旋系统和凝聚态物理体系的严格解模型研究，取得了一系列在国际上颇具影响力的研究成果。已发表百余篇SCI论文，包括世界物理顶尖期刊《Science》、《Review of Modern Physics》、《Report on Progress in Physics》、《Advance in Physics》、《Nature》子刊、《National Science Review》、《Physical Review Letters》等。