Related papers: The two-fluid model with superfluid entropy
We derive the hydrodynamic equations of motion of solid and supersolid 4He, that describe the collective modes of these phases. In particular, the usual hydrodynamics is modified in such a way that it leads to the presence of a propagating…
We construct a model of non-uniform condensate having a spatially modulated complex order parameter that makes it kinematically an x-ray solid, i.e., a real mass density wave, but one admitting an associated superfluid flow. Intrinsic to…
Quantum Monte Carlo simulations are used to investigate the two-dimensional superfluid properties of the hard-core boson model, which show a strong dependence on particle density and disorder. We obtain further evidence that a half-filled…
We study a mean-field model of superconducting vortices in a II-type superconductor. We prove the global solvability of the problem about a flux of superconducting vortices through a given domain and also analyse the regularity of weak…
The famous two-fluid model of finite-temperature superfluids has been recently extended to describe the mixed classical-superfluid dynamics of the newly discovered supersolid phase of matter. We show that for rigidly rotating supersolids…
A calculation of the transverse sound velocity as a function of excess entropy is presented for several simple fluids, including the Lennard-Jones, Yukawa, one-component plasma, inverse-power law (soft sphere) and hard sphere models. A…
The onset mechanism of superfluidity is examined by taking the case of the capillary flow of liquid helium 4. In the capillary flow, a substantial fall of the shear viscosity has been observed in the normal phase (lambda point<T<3.7K). In…
Superfluid helium is an intimate mixture of a viscous normal fluid, with continuous vorticity, and an inviscid superfluid, where vorticity is constrained to thin, stable topological defects. One mechanism to generate turbulence in this…
We study the propagation of a density wave in a magnetically trapped Bose-Einstein condensate at finite temperatures. The thermal cloud is in the hydrodynamic regime and the system is therefore described by the two-fluid model. A…
The results of numerical experiments on chaotic ('turbulent') dynamics of the second sound in helium II are presented and discussed based on a very simple model proposed and theoretically studied recently by Khalatnikov and Kroyter. Using a…
We present a dissipative hydrodynamic theory of "s-wave dipole superfluids" that arise in phases of translation-invariant and dipole-symmetric models in which the U(1) symmetry is spontaneously broken. The hydrodynamic description is subtle…
We present solid evidence for the existence of a well-defined Higgs amplitude mode in two-dimensional relativistic field theories based on analytically continued results from quantum Monte Carlo simulations of the Bose-Hubbard model in the…
The article deals with the sin-Gordon model and considers the interaction of breathers localized on moving impurities. Numerical simulation of collective behavior of such objects revealed the analogy between the models properties and the…
We propose a theory which deals with the structure and interactions of volume elements in liquid helium II. The approach consists of two nested models linked via parametric space. The short-wavelength part describes the interior structure…
We develop a new framework for the modelling of charged fluid dynamics in general relativity. The model, which builds on a recently developed variational multi-fluid model for dissipative fluids, accounts for relevant effects like the…
We solve numerically for the first time the two-fluid, Hall--Vinen--Bekarevich--Khalatnikov (HVBK) equations for a He-II-like superfluid contained in a differentially rotating, spherical shell, generalizing previous simulations of viscous…
We report on studies of quantum turbulence with second-sound in superfluid 4He in which the turbulence is generated by the flow of the superfluid component through a wide square channel, the ends of which are plugged with sintered silver…
Helium nanodroplets and trapped Bose-Einstein condensates in dilute atomic gases offer complementary views of fundamental aspects of quantum many-body systems. We discuss analogies and differences, stressing their common theoretical…
We have performed quantum Monte Carlo simulations measuring the finite size and temperature superfluid response of helium-4 to the linear and rotational motion of the walls of a nanopore. Within the two-fluid model, the portion of the…
We analyze the effect of a gravitational field on the sound modes of superfluids. We derive an instability condition that generalizes the well known Jeans instability of the sound mode in normal fluids. We discuss potential experimental…