Bifurcations, stability, and mode evolution in segregated condensate mixtures

Abstract

We present new features of low energy Bogoliubov quasiparticle excitations of a two component Bose-Einstein condensate (TBEC) in quasi-2D geometry at zero temperature using Hartree-Fock-Bogoliubov (HFB). We, in particular, consider the TBECs of ${}^{133}$Cs~-${}^{87}$Rb and ${}^{85}$Rb~-${}^{87}$Rb, and show specific features in the low energy excitation spectrum as a function of the interaction strength. For ${}^{85}$Rb~-${}^{87}$Rb TBEC, the appearance of a new zero energy mode is observed. Whereas for ${}^{133}$Cs~-${}^{87}$Rb TBEC we report a bifurcation of the softened Kohn mode at the point of transition from miscible to immiscible domain. The lower energy mode, after the bifurcation, goes soft and becomes a new Goldstone mode of the system.

The paper has 9 pages and 12 figures

References in corpus (12)

• Creation of ultracold ${}^{87}$RbCs molecules in the rovibrational ground state
• Dual-Species Bose-Einstein Condensate of ${}^{87}$Rb and ${}^{133}$Cs
• C programs for solving the time-dependent Gross-Pitaevskii equation in a fully anisotropic trap
• Observation of Heteronuclear Feshbach Molecules from a ${}^{85}$Rb - ${}^{87}$Rb gas
• Production of a dual-species Bose-Einstein condensate of Rb and Cs atoms
• Tunable dual-species Bose-Einstein condensates of ${}^{39}$K and ${}^{87}$Rb
• Controlling the Rotational and Hyperfine State of Ultracold ${}^{87}$Rb${}^{133}$Cs Molecules
• Quasi-Nambu-Goldstone Modes in Bose-Einstein Condensates
• Equilibrium solutions of immiscible two-species Bose-Einstein condensates in perturbed harmonic traps
• Fluctuation driven topological transition of binary condensates in optical lattices
• Fluctuation and interaction induced instability of dark solitons in single and binary condensates
• Evolution of Goldstone mode in binary condensate mixtures

Cited by in corpus (3)

• Segregated quantum phases of dipolar bosonic mixtures in two-dimensional optical lattices
• FACt: FORTRAN toolbox for calculating fluctuations in atomic condensates
• Effect of Rashba spin-orbit and Rabi couplings on the excitation spectrum of binary Bose-Einstein condensates