Related papers: Collective Modes in Supersolid 4He
In this thesis we investigate the instabilities of superfluids at finite superflow by means of a hydrodynamical approach. We find that at a finite value of the background superfluid velocity a hydrodynamic collective mode crosses to the…
We discuss a unified flow theory which in a single system of hyperbolic partial differential equations (PDEs) can describe the two main branches of continuum mechanics, fluid dynamics, and solid dynamics. The fundamental difference from the…
The equations of motion of pair-like excitations in the superconducting state are studied for various types of pairing using the random phase approximation. The collective modes are computed of a layered electron gas described by a $t-t'$…
Assuming that the well-confirmed non-classical rotational inertia (NCRI) effect in solid $^4$He, suggested by Leggett, indicates supersolid behavior, we make a number of remarks about both theory and experiment. (1) The long-wavelength,…
In Fermi superfluids, like superfluid 3He, the viscous normal component can be considered to be stationary with respect to the container. The normal component interacts with the superfluid component via mutual friction which damps the…
The local equilibrium approach previously developed by the Authors [J. Mabillard and P. Gaspard, J. Stat. Mech. (2020) 103203] for matter with broken symmetries is applied to crystalline solids. The macroscopic hydrodynamics of crystals and…
The B phase of superfluid 3He can be cooled into the pure superfluid regime, where the thermal quasiparticle density is negligible. The bulk superfluid is surrounded by a quantum well at the boundaries of the container, confining a sea of…
The structure and energetics of superflow around quantized vortices, and the motion inherited by these vortices from this superflow, are explored in the general setting of the superfluidity of helium-four in arbitrary dimensions. The…
We numerically study the dynamical properties of a mixture consisting of a dipolar condensate and a degenerate Fermi gas in a quasi-one-dimensional geometry. In particular, we focus on the system's response to a temporal variation in the…
The A and B phases of superfluid 3 He have vector degrees of freedom that reflect their characteristic broken symmetries, respectively chiral and spin-orbit rotation axes. Anisotropic disorder in the superfluid, imbibed in uniformly…
We analyse a one-dimensional model of hard particles, within ensembles of trajectories that are conditioned (or biased) to atypical values of the time-averaged dynamical activity. We analyse two phenomena that are associated with these…
We investigate the physical properties of steady flows in a holographic first-order phase transition model, extending from the thermodynamics at equilibrium to the real-time dynamics far from equilibrium. Through spinodal decomposition or…
We present a simple quantum mechanical model describing excited rotational states of molecules in superfluid helium nanodroplets, as recently studied in non-adiabatic molecular alignment experiments [Cherepanov et al., Phys. Rev. A 104,…
In this work we analyze the hydrodynamics of a $p-$ wave superfluid on its strongly coupled regime by considering its holographic description. We obtain the poles of the retarded Green function through the computation of the quasi-normal…
We investigate the convergence of relativistic hydrodynamics in charged fluids, within the framework of holography. On the one hand, we consider the analyticity properties of the dispersion relations of the hydrodynamic modes on the complex…
In equilibrium and supercooled liquids, polymorphism is manifested by thermodynamic regions defined in the phase diagram, which are predominantly of different short- and medium-range order (local structure). It is found that on the phase…
Superfluid 4He, the first superfluid ever discovered, is in some ways the least well understood. Unlike 3He superfluid, or the variety of Bose-Einstein condensates of ultracold gases, superfluid 4He is a very dense liquid of strongly…
Our recent study suggested that a fully classical mechanical approximation of the two-fluid model of superfluid helium-4 based on smoothed-particle hydrodynamics (SPH) is equivalent to solving a many-body quantum mechanical equation under…
We have carried out torsional oscillator experiments on solid $^4$He at temperatures between 1.3K and 1.9K. We discovered phenomena similar to those observed at temperatures below 0.2K, which currently are under debate regarding their…
The problem studied in this paper is to obtain the equations describing sound propagation in a consolidated porous medium filled with superfluid, determine the elastic coefficients, appearing in the equations, in terms of physically…