One-dimensional superfluid Bose-Fermi mixture: Mixing, demixing, and bright solitons

被引:38
作者
Adhikari, Sadhan K. [1 ]
Salasnich, Luca
机构
[1] Univ Nacl Estadual Sao Paulo, Inst Fis Teor, BR-01405900 Sao Paulo, Brazil
[2] Univ Padua, Dipartimento Fis, Univ Padua, CNR INFM, I-35131 Padua, Italy
[3] Univ Padua, Dipartimento Fis, Univ Padua, CNISM, I-35131 Padua, Italy
来源
PHYSICAL REVIEW A | 2007年 / 76卷 / 02期
关键词
D O I
10.1103/PhysRevA.76.023612
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
We study an ultracold and dilute superfluid Bose-Fermi mixture confined in a strictly one-dimensional (1D) atomic waveguide by using a set of coupled nonlinear mean-field equations obtained from the Lieb-Liniger energy density for bosons and the Gaudin-Yang energy density for fermions. We consider a finite Bose-Fermi interatomic strength g(bf) and both periodic and open boundary conditions. We find that with periodic boundary conditions-i.e., in a quasi-1D ring-a uniform Bose-Fermi mixture is stable only with a large fermionic density. We predict that at small fermionic densities the ground state of the system displays demixing if g(bf)> 0 and may become a localized Bose-Fermi bright soliton for g(bf)< 0. Finally, we show, using variational and numerical solutions of the mean-field equations, that with open boundary conditions-i.e., in a quasi-1D cylinder-the Bose-Fermi bright soliton is the unique ground state of the system with a finite number of particles, which could exhibit a partial mixing-demixing transition. In this case the bright solitons are demonstrated to be dynamically stable. The experimental realization of these Bose-Fermi bright solitons seems possible with present setups.
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页数:11
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