Description of Research Area

“Synergy of Fluctuation and Structure” in Quantum Hydrodynamics

Research Subject

We study theoretically and numerically quantum hydrodynamics from the viewpoint of nonlinear and nonequilibrium physics. The systems we investigate are superfluid helium and atomic Bose-Einstein condensates (BECs). The first target is coupled turbulence of superfluid and normal fluid in superfluid helium. Recent experiments succeeded in visualizing quantized vortices and normal fluid profile. Being motivated by these results, we have studied quantum turbulence in a channel to find the characteristic fluctuation of vortices and the logarithmic velocity profile in turbulent boundary layer. Since these studies fixed the profile of the normal fluid flow, we try to study coupled dynamics of quantized vortices and the Navier-Stokes equation describing the normal fluid flow. The second target is multi-component BECs. We study the universal law in quantum hydrodynamics following the ideas of nonequilibrium critical phenomena.