Bose-Einstein Condensates in a Synthetic Magnetic Field with Tunable Orientation

TL;DR

This paper explores the behavior of spinor Bose-Einstein condensates under a tunable synthetic magnetic field, revealing controllable collective excitations and mode dynamics with potential applications in quantum simulation and sensing.

Contribution

It introduces a hydrodynamic model for condensates in a synthetic magnetic field with tunable orientation, validated by simulations, advancing understanding of collective modes and excitations.

Findings

Decomposition of dipole motion into coupled transverse and decoupled longitudinal modes.

Controllable Foucault-like precession and bi-conical trajectories.

Excitation of multiple coupled quadrupole modes upon field orientation quench.

Abstract

We systematically investigate the ground state and dynamics of spinor Bose-Einstein condensates subject to a position-dependent detuning. This detuning induces three related quantities-a synthetic magnetic field, an angular velocity, and an angular momentum-which, due to trap anisotropy, may point in different directions. When the dipole frequencies along the three symmetric axes of the harmonic trap are degenerate, the dipole motion can decompose into two coupled transverse modes in the plane perpendicular to the synthetic magnetic field, and another decoupled longitudinal mode, enabling controllable Foucault-like precession or bi-conical trajectories depending on the excitation protocol. Furthermore, quenching the orientation of the synthetic magnetic field excites multiple coupled quadrupole modes. We develop a hydrodynamic theory whose predictions match well with Gross-Pitaevskii simulations. This study contributes to a deeper understanding of the effects of the synthetic magnetic field and the excitations of the collective mode in quantum fluids, providing a foundation for future developments in quantum simulation and high-precision sensing technologies.