Exact results for polaron and molecule in one-dimensional spin-1/2 Fermi gas
| Autor: | Mao, Runxin, Guan, X. W., Wu, Biao |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Phys. Rev. A 94, 043645 (2016) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevA.94.043645 |
| Popis: | Using exact Bethe ansatz (BA) 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. Comment: 11 pages, 7 figures |
| Databáze: | arXiv |
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