Exact results for polaron and molecule in one-dimensional spin-1/2 Fermi gas
Exact results for polaron and molecule in one-dimensional spin-1/2 Fermi gas
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一维自旋 1/2 费米气体中极化子和分子的精确结果
DOI：
10.1103/physreva.94.043645
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发表时间：
2016-10
期刊：
影响因子：
--
通讯作者：
吴飙
中科院分区：
文献类型：
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作者：
毛润欣;管习文;吴飙
使用精确的 Bethe ansatz 解，我们表明，浸入具有弱吸引力的完全极化的自旋向上费米海中的自旋向下费米子被周围的自旋向上费米子修饰，形成极化子的一维模拟。随着吸引力变强，自旋向下的费米子与一个自旋向上的费米子结合，形成紧密结合的分子。在整个相互作用状态中，从极化子到分子态的交叉通过激发光谱、有效质量、结合能和动能的精确结果得到充分证明。此外，极化子和分子之间的明显区别是通过概率分布、单粒子约化密度矩阵和密度-密度相关性来构想的，这些都是直接从 Bethe ansatz 波函数计算出来的。这种极化子-分子交叉呈现出浸入具有一维吸引力的费米子介质中的杂质的普遍性质。
Using exact Bethe ansatz solutions, we show that a spin-down fermion immersed into a fully polarized spin-up Fermi sea with a weak attraction is dressed by the surrounding spin-up fermions to form the one-dimensional analog of a polaron. As the attraction becomes strong, the spin-down fermion binds with one spin-up fermion to form a tightly bound molecule. Throughout the whole interaction regime, a crossover from the polaron to a molecule state is fully demonstrated through exact results of the excitation spectrum, the effective mass, binding energy and kinetic energy. Furthermore, a clear distinction between the polaron and molecule is conceived by the probability distribution, single-particle reduced density matrix, and density-density correlations, which are calculated directly from the Bethe ansatz wave function. Such a polaron-molecule crossover presents a universal nature of an impurity immersed into a fermionic medium with an attraction in one dimension.
DOI：
10.1017/cbo9780511524332.005
发表时间：
1999
期刊：
--
影响因子：
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作者：
Minoru Takahashi
通讯作者：
Minoru Takahashi