2016/03/31 by J. Armaitis, R. A. Duine
Physics and Astronomy · #Atomic and Subatomic Physics Research #Bose gas #Bose–Einstein condensate #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Physics #Quantum mechanics #Quantum, superfluid, helium dynamics #Spin (aerodynamics) #Spinor #Superfluidity #cond-mat.mes-hall #cond-mat.quant-gas
paper · pdf · doi:10.1103/physreva.95.053607
published as Phys. Rev. A 95, 053607 (2017)
arxiv created 2017/05/04 · openalex publication_date 2017/05/04 · arxiv updated 2017/05/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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.