Excitation of a Dipole Topological Mode in a Strongly Coupled Two-Component Bose-Einstein Condensate

TL;DR

This paper demonstrates how strong coupling between hyperfine states in a Bose-Einstein condensate can induce topological modes and modulate Rabi oscillations due to gravitationally offset trapping potentials.

Contribution

It introduces a theoretical model showing the excitation of a dipole topological mode in a strongly coupled two-component BEC with gravitational offset effects.

Findings

Population transfer to antisymmetric topological mode

Modulation of Rabi oscillations and fringe visibility

Theoretical description using mean-field theory

Abstract

Two internal hyperfine states of a Bose-Einstein condensate in a dilute magnetically trapped gas of ${}^{87}$Rb atoms are strongly coupled by an external field that drives Rabi oscillations between the internal states. Due to their different magnetic moments and the force of gravity, the trapping potentials for the two states are offset along the vertical axis, so that the dynamics of the internal and external degrees of freedom are inseparable. The rapid cycling between internal atomic states in the displaced traps results in an adiabatic transfer of population from the condensate ground state to its first antisymmetric topological mode. This has a pronounced effect on the internal Rabi oscillations, modulating the fringe visibility in a manner reminiscent of collapses and revivals. We present a detailed theoretical description based on zero-temperature mean-field theory.