Related papers: Superfluidity of Dense $^4$He in Vycor
Superfluid $^4$He (He-II) is a widely studied model system for exploring finite-size effects in strongly confined geometries. Here, we study He-II confined in mm-scale channels of 25 and 50 nm height at high pressures using a nanofluidic…
Defects in the multi-dimensional macroscopic quantum field of the He-3 superfluids are localized objects with a topological charge and are topologically stable. They include point-like objects, vortex lines, planar domain-wall-like…
Recent experiments have shown that rising the temperature of a dipolar gas under certain conditions leads to a transition to a supersolid state. Here, we employ the path integral Monte Carlo method, which exactly accounts for both thermal…
We argue that the three key phenomena recently observed in solid $^4$He---mass supertransport, anomalous isochoric compressibility (syringe effect), and giant plasticity---are closely linked to each other through the physics of an…
Molecular para-hydrogen has been proposed theoretically as a possible candidate for superfluidity, but the eventual superfluid transition is hindered by its crystallization. In this work, we study a metastable non crystalline phase of bulk…
We obtain the von K\'arm\'an-Howarth relation for the stochastically forced three-dimensional Hall-Vinen-Bekharvich-Khalatnikov (3D HVBK) model of superfluid turbulence in Helium ($^4$He) by using the generating-functional approach. We…
The binding energies of two-dimensional clusters (puddles) of $^4$He are calculated in the framework of the diffusion Monte Carlo method. The results are very well fitted by a mass formula in powers of $x=N^{-1/2}$, where $N$ is the number…
The second layer of He-4 adsorbed on a graphite substrate is studied by Quantum Monte Carlo simulations. We make use of a microscopic model of the substrate fully accounting for its corrugation, and compare the results to those obtained…
We employ a simple model to describe the phase behavior of 4He and Ar in a hypothetical porous material consisting of a regular array of infinitely long, solid, parallel cylinders. We find that high porosity geometries exhibit two…
In this work we investigate the quantum nature of bcc $^{4}$He. We show that it is a solid phase with an Off-Diagonal Long Range Order of coherently oscillating local electric dipole moments. These dipoles arise from the correlated…
We compare the decay of turbulence in superfluid $^4$He produced by a moving grid to the decay of turbulence created by either impulsive spin-down to rest or by intense ion injection. In all cases the vortex line density $L$ decays at late…
Using a path-integral Monte Carlo method for simulating superfluid quantum films, we investigate helium layers adsorbed on a substrate consisting of graphite plus two solid helium layers. Our results for the promotion densities and the…
The adsorption of highly \textit{oppositely} charged flexible polyelectrolytes onto a charged spherical surface is investigated by means of Monte Carlo simulations in a fashion which resembles the layer-by-layer deposition technique…
Superfluid 3He is an unconventional neutral superfluid in a p-wave state with three different superfluid phases each identified by a unique set of characteristic broken symmetries and non- trivial topology. Despite natural immunity of 3He…
We report clear experimental signatures of the theoretically unexpected gas-liquid transition in the first three monolayers of $^3$He adsorbed on graphite. The transition is inferred from the linear density dependence of the…
Crystal grains of solid $^4$He can move in relation to each other even when embedded inside the solid. In this work, we characterize a macroscopic motion of solid hcp $^4$He composed of such grains. Motion is induced by applying an external…
Recent experiments have detected 4He supersolidity, but the observed transition is rather unusual. In this paper, we describe a supersolid as a normal lattice suffused by a Bose gas. With this approach, we can explain the central aspects of…
The heat capacity of a small amount of $^3$He atoms dissolved in submonolayer $^4$He film has been measured. The measured heat capacity is finite and suggests that $^3$He atoms are mobile at an areal density regime higher than that of the…
We use Quantum Monte Carlo simulations and exact diagonalization to explore the phase diagram of the Bose-Hubbard model with an additional superlattice potential. We first analyze the properties of superfluid and insulating phases present…
Peculiar dynamics of a free surface of the superfluid 4He has been observed experimentally with a newly established technique utilizing a number of electrically charged fine metal particles trapped electrically at the surface by Moroshkin…