Spin-charge separation in a one-dimensional Fermi gas with tunable interactions
Spin-charge separation in a one-dimensional Fermi gas with tunable interactions
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具有可调相互作用的一维费米气体中的自旋电荷分离
DOI：
10.1126/science.abn1719
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发表时间：
2022
期刊：
影响因子：
56.9
通讯作者：
all G. Hulet
中科院分区：
文献类型：
--
作者：
Ruwan Senaratne;Danyel Cavazos-Cavazos;Sheng Wang;Feng He;Ya-Ting Chang;Aashish Kafle;Han Pu;Xi-Wen Guan;R;all G. Hulet
被限制在周期势中的超冷原子已被证明是对复杂多体系统进行量子模拟的有力工具。我们将费米子限制在一维空间来实现Tomonaga-Luttinger液体模型，该模型描述了它们的低能激发的高度集体性质。我们使用布拉格光谱直接激发自旋或电荷波的各种强度的排斥相互作用。我们观察到自旋和电荷激发的速度随着相互作用的增加而向相反的方向移动，这是自旋-电荷分离的标志。激发光谱与Yang-Gaudin模型和Tomonaga-Luttinger液体理论的精确解定量一致。此外，我们确定的非线性校正的影响，该理论所产生的带曲率和背散射。
Ultracold atoms confined to periodic potentials have proven to be a powerful tool for quantum simulation of complex many-body systems. We confine fermions to one dimension to realize the Tomonaga-Luttinger liquid model, which describes the highly collective nature of their low-energy excitations. We use Bragg spectroscopy to directly excite either the spin or charge waves for various strengths of repulsive interaction. We observe that the velocity of the spin and charge excitations shift in opposite directions with increasing interaction, a hallmark of spin-charge separation. The excitation spectra are in quantitative agreement with the exact solution of the Yang-Gaudin model and the Tomonaga-Luttinger liquid theory. Furthermore, we identify effects of nonlinear corrections to this theory that arise from band curvature and back-scattering.