2020/11/12 by Renyuan Liao
Physics and Astronomy · #Binary number #Boson #Cold Atom Physics and Bose-Einstein Condensates #Phase (matter) #Phase diagram #Physics of Superconductivity and Magnetism #Quantum #Quantum many-body systems #Quasiparticle #Spin (aerodynamics) #Structure factor #cond-mat.quant-gas #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevresearch.2.043218
published as Phys. Rev. Research 2, 043218 (2020) · 6 pages, 3 figures. arXiv admin note: text overlap with arXiv:2007.00409
openalex publication_date 2020/11/12 · openalex created_date 2020/11/23 · arxiv created 2020/12/02 · arxiv updated 2020/12/03 · openalex updated_date 2026/08/05
We develop a functional integral formulation for binary Bose-Einstein condensates coupled to polarized fermions. We find that spin-dependent fermion-mediated interactions have dramatic effects on the properties of the binary condensates. The quasiparticle spectrum features two branches. The upper branch, which is of density nature, gets modified by the induced interactions, while the lower branch, which is of spin nature, is left intact. The ground-state phase diagram consists of stable region of miscible phases and unstable region toward phase separation. In the stable region, it is further classified by the damping of excitations of the upper branch. We show that it is possible to find region of well-defined, long-lived quasiparticle excitations by tuning relevant parameters, such as boson-fermion mass ratio, boson-fermion number density ratio, and interspecies interactions between bosons as well. We explore the effects of quantum fluctuation due to the effective potential on the binary condensates. It turns out that both the density structure factor and spin density structure factor fulfill the Feynman relation, except that the latter is immune to the fermion-mediated interactions.