Superfluid properties of magnetized 3He-B in a disordered medium

The influence of nonmagnetic impurity scattering on the anisotropy of the magnetized B phase of superfluid ³He is investigated theoretically. The contribution of the impurity-induced spin-singlet superfluid correlations in the presence of the p-wave Cooper pairing is revealed. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 2, 95–100 (25 January 1996) Published in English in the original Russian journal. Edited by Steve Torstveit.     

Fluctuations and Correlations of Pure Quantum Turbulence in Superfluid 3He-B

We describe the first measurements of line-density fluctuations and spatial correlations of quantum turbulence in superfluid 3He-B. All of the measurements are performed in the low-temperature regime, where the normal-fluid density is negligible. The quantum turbulence is generated by a vibrating grid. The vortex-line density is found to have large length-scale correlations, indicating large-scale collective motion of vortices. Furthermore, we find that the power spectrum of fluctuations versus frequency obeys a -5/3 power law which verifies recent speculations that this behavior is a generic feature of fully developed quantum turbulence, reminiscent of the Kolmogorov spectrum for velocity fluctuations in classical turbulence.     

Quantum Hydrodynamics,Rotating Superfluid and Gravitational Anomaly

Journal of Experimental and Theoretical Physics - We present a consistent scheme of quantization of chiral flows (flows with extensive vorticity) in ideal hydrodynamics in two dimensions. Chiral...     

Gravitational Effects on the Vortex Distribution in Relativistic Superfluid Stars

Neutron stars are supposed to be mainly formed by a neutron superfluid. The angular momentum is given by the vortex array within the fluid, and a good account of the observable effects is determined by its coupling with the crust. In this article we show that the gravitational field introduces important modifications in the vortex distribution and shape. The inertial frame dragging on the quantum fluid produces a decrease in the vortex density, which for realistic models is in the order of 15%. This effect is relevant for neutron star rotation models and can provide a good framework for checking the quantum effect of the frame dragging.     

Inhomogeneous Vortex Patterns in Rotating Bose-Einstein Condensates

We consider a 2D rotating Bose gas described by the Gross-Pitaevskii (GP) theory and investigate the properties of the ground state of the theory for rotational speeds close to the critical speed for vortex nucleation. While one could expect that the vortex distribution should be homogeneous within the condensate we prove by means of an asymptotic analysis in the strongly interacting (Thomas-Fermi) regime that it is not. More precisely we rigorously derive a formula due to Sheehy and Radzihovsky (Phys Rev A 70:063620(R), 2004) for the vortex distribution, a consequence of which is that the vortex distribution is strongly inhomogeneous close to the critical speed and gradually homogenizes when the rotation speed is increased. From the mathematical point of view, a novelty of our approach is that we do not use any compactness argument in the proof, but instead provide explicit estimates on the difference between the vorticity measure of the GP ground state and the minimizer of a certain renormalized energy functional.     

Quantized Superfluid Vortex Filaments Induced by the Axial Flow Effect

We report the quantized superfluid vortex filaments induced by the axial flow effect, which exhibit intriguing loop structures on helical vortexes. Such new vortex filaments correspond to a series of soliton excitations including the multipeak soliton, W-shaped soliton, and anti-dark soliton, which have no analogue when the axial flow effect is absent. In particular, we show that the vortex filaments induced by the multipeak soliton and W-shaped soliton arise from the dual action of bending and twisting of the vortex, while the vortex filament induced by the anti-dark soliton is caused only by the bending action, which is consistent with the case of the standard bright soliton. These results will deepen our understanding of breather-induced vortex filaments and will be helpful for controllable ring-like excitations on vortices.     

Magnetoacoustic spectroscopy in superfluid 3He-B

We have used the acoustic Faraday effect in superfluid 3He to perform high resolution spectroscopy of an excited state of the superfluid condensate, called the imaginary squashing mode. With acoustic cavity interferometry we measure the rotation of the plane of polarization of a transverse sound wave propagating in the direction of the magnetic field from which we determine the Zeeman energy of the mode. We interpret the Landé g factor, combined with the zero-field energies of this excited state, using the theory of Sauls and Serene, to calculate the strength of f-wave interactions in 3He.     

Vortex Dynamics in Spin-1 Spin-orbit-coupled Rotating Bose-Einstein Condensates

International Journal of Theoretical Physics - We study the vortex dynamics of spin-orbit-coupled (SOC) spin-1 Bose-Einstein condensates by numerical simulations of the Gross-Pitaevskii equation....     

Coherent Vortex in Two-Dimensional Turbulence around a Rotating Disc

JETP Letters - We consider the structure of a coherent vortex formed around a solid rotating disc in two-dimensional turbulent flow. We find the average velocity profile of the coherent vortex for...     

Spinning particle-like solitons in superfluid3He-B

Particle-like topological solitons in superfluid³He-B are studied. The existing treatment of such objects indicates that static solitons have a free energy proportional to their size. They are thus unstable and will shrink to zero size. In the present work we consider spinning solitons whose size originates from an angular momentum barrier. In order for the solitons to be meaningfully described by theB phase their free energy must be small compared with their condensation energy. This requires that the angular momentum be large and effectively they are in the classical continuum limit. A detailed consideration of the variational procedure required to determine the soliton profile is presented allowing estimates of their size and energy. Address as from October 1991: Physics Institute, Faculty of Liberal Arts, Shizuoka University, Shizuoka 422, Japan