Superfluidity and spin superfluidity in spinor Bose gases

Abstract

We show that spinor Bose gases subject to a quadratic Zeeman effect exhibit coexisting superfluidity and spin superfluidity, and study the interplay between these two distinct types of superfluidity. To illustrate that the basic principles governing these two types of superfluidity are the same, we describe the magnetization and particle-density dynamics in a single hydrodynamic framework. In this description spin and mass supercurrents are driven by their respective chemical potential gradients. As an application, we propose an experimentally accessible stationary state, where the two types of supercurrents counterflow and cancel each other, thus resulting in no mass transport. Furthermore, we propose a straightforward setup to probe spin superfluidity by measuring the in-plane magnetization angle of the whole cloud of atoms. We verify the robustness of these findings by evaluating the four-magnon collision time, and find that the time scale for coherent (superfluid) dynamics is separated from that of the slower incoherent dynamics by one order of magnitude. Comparing the atom and magnon kinetics reveals that while the former can be hydrodynamic, the latter is typically collisionless under most experimental conditions. This implies that, while our zero-temperature hydrodynamic equations are a valid description of spin transport in Bose gases, a hydrodynamic description that treats both mass and spin transport at finite temperatures may not be readily feasible.

References in corpus (15)

• Superconducting Spintronics
• Spontaneous symmetry breaking in a quenched ferromagnetic spinor Bose condensate
• Bose-Einstein Condensation in Magnetic Insulators
• Quench-induced supercurrents in an annular Bose gas
• Broken axisymmetry phase of a spin-1 ferromagnetic Bose-Einstein condensate
• Two-Fluid Theory for Spin Superfluidity in Magnetic Insulators
• Can Spinor Dipolar Effects be Observed in Bose-Einstein Condensates?
• Coherent magnon optics in a ferromagnetic spinor Bose-Einstein condensate
• Long wavelength spin dynamics of ferromagnetic condensates
• Dynamical instability of the XY spiral state of ferromagnetic condensates
• Condensing magnons in a degenerate ferromagnetic spinor Bose gas
• Hydrodynamic modes of partially condensed Bose mixtures
• Superfluidity of pure spin current in ultracold Bose gases
• Spintronics and Magnon Bose-Einstein Condensation
• Upper bound of one-magnon excitation and lower bound of effective mass for ferromagnetic spinor Bose and Fermi gases

Cited by in corpus (9)

• Observation of Spin Superfluidity in a Bose Gas Mixture
• Observation of a strongly ferromagnetic spinor Bose-Einstein condensate
• Superfluid spin transport in ferro- and antiferromagnets
• Critical Energy Dissipation in a Binary Superfluid Gas by a Moving Magnetic Obstacle
• Spin and mass superfluidity in ferromagnetic spin-1 Bose-Einstein condensate
• Superfluid spin transport in magnetically ordered solids
• Magnon spin capacitor
• Berezinskii-Kosterlitz-Thouless transitions in a ferromagnetic superfluid: effects of axial magnetization
• Interplay of spin and mass superfluidity in antiferromagnetic spin-1 BEC and bicirculation vortices