Analytical and numerical studies of BoseFermi mixtures in a onedimensional harmonic trap
Abstract
In this paper we study a mixed system of bosons and fermions with up to six particles in total. All particles are assumed to have the same mass. The twobody interactions are repulsive and are assumed to have equal strength in both the BoseBose and the FermiBoson channels. The particles are confined externally by a harmonic oscillator onebody potential. For the case of four particles, two identical fermions and two identical bosons, we focus on the strongly interacting regime and analyze the system using both an analytical approach and density matrix renormalization group calculations using a discrete version of the underlying continuum Hamiltonian. This provides us with insight into both the ground state and the manifold of excited states that are almost degenerate for large interaction strength. Our results show great variation in the density profiles for bosons and fermions in different states for strongly interacting mixtures. By moving to slightly larger systems, we find that the ground state of balanced mixtures of four to six particles tends to separate bosons and fermions for strong (repulsive) interactions. On the other hand, in imbalanced BoseFermi mixtures we find pronounced oddeven effects in systems of five particles. These fewbody results suggest that question of phase separation in onedimensional confined mixtures are very sensitive to system composition, both for the ground state and the excited states.
 Publication:

Journal of Physics B Atomic Molecular Physics
 Pub Date:
 July 2017
 DOI:
 10.1088/13616455/aa7797
 arXiv:
 arXiv:1703.01836
 Bibcode:
 2017JPhB...50n4002D
 Keywords:

 Condensed Matter  Quantum Gases;
 Quantum Physics
 EPrint:
 13 pages, 6 figures, slightly revised version