Related papers: Specific heat of thin $^4$He films on graphite
This paper is an expanded edition of the rapid communication published several years ago by the author (Phys. Rev. B, v76, 041402(R), 2007) on the simulation of wetting transition of water on graphite, aiming to provide more details on the…
The second-layer phase diagrams of $^4$He and $^3$He adsorbed on graphite are investigated. Intrinsically rounded specific-heat anomalies are observed at 1.4 and 0.9 K, respectively, over extended density regions in between the liquid and…
Quantum Monte Carlo simulations at zero temperature of a $^3$He monolayer adsorbed on graphite, either clean or preplated with $^4$He, unexpectedly point to a gas-liquid phase transition at a very low areal density of the order of…
We report high-precision heat-capacity measurements of submonolayer $^3$He adsorbed on highly crystalline graphite, revealing new aspects of the commensurate$-$incommensurate transition. Below 1\~K, two possible striped domain-wall phases…
In order to resolve the controversy about the low density region of the phase diagram of the 4He monolayer on graphite, we have undertaken a path integral Monte Carlo study of the system. We provide direct evidence that the low density…
Extensive Monte Carlo simulations of helium-4 monolayer films adsorbed on weak substrates have been carried out, aimed at ascertaining the possible occurrence of a quasi-two-dimensional supersolid phase. Only crystalline films not…
We study the low temperature properties of a single layer of parahydrogen adsorbed on graphene, by means of Quantum Monte Carlo simulations. The computed phase diagram is very similar to that of helium on the same substrate, featuring…
Recent heat-capacity experiments show quite unambiguously the existence of a liquid $^3$He phase adsorbed on graphite. This liquid is stable at an extremely low density, possibly one of the lowest found in Nature. Previous theoretical…
We report preliminary heat capacity and vapor pressure measurements of the first and second layers of 4He adsorbed on ZYX graphite. ZYX is known to have much better crystallinity than Grafoil, the most commonly-used exfoliated graphite…
The calculation of the He4 energy and specific heat is carried out in a wide temperature range within the two-time temperature Green functions approach. The approximation improving the random phase approximation is developed providing the…
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…
The specific heat of the $x-y$ model is studied on cubic lattices of sizes $L \times L \times L$ and on lattices $L \times L \times H$ with $L \gg H$ (i.e. on lattices representing a film geometry) using the Cluster Monte Carlo method.…
Thin $^4$He films adsorbed to weakly attractive substrates form nearly 2D layers. We describe the vortices in 2D superfluid $^4$He like quasiparticles. With the aid of a variational many-body calculation we estimate their inertial mass and…
A quantum Monte Carlo approach, considering all the corrugation effects, was used to calculate the complete phase diagram of the second $^3$He layer adsorbed on graphite. We found that a first-layer triangular solid was in equilibrium with…
The superfluid response of nanoscale size quasi-2D He-4 droplets adsorbed on a graphite substrate is investigated by computer simulations. It is found that clusters comprising as few as 7 atoms are stable at temperatures lower than < 0.15…
We made heat-capacity measurements of two dimensional (2D) $^3$He adsorbed on graphite preplated with monolayer $^4$He in a wide temperature range (0.1 $\leq T \leq$ 80 mK) at densities higher than that for the 4/7 phase (= 6.8 nm$^{-2}$).…
Adsorption of para-hydrogen films on Alkali metals substrates at low temperature is studied theoretically by means of Path Integral Monte Carlo simulations. Realistic potentials are utilized to model the interaction between two…
Quantum Monte Carlo simulations at zero temperature of an ensemble of He-3 atoms adsorbed on Mg and Alkali substrates yield strong evidence of a thermodynamically stable liquid He-3 monolayer on all Alkali substrates, with the possible…
In the underdoped, overdoped, Zn-doped or stripe-forming regions of high-$T_{c}$ cuprate superconductors (HTSC), the superfluid density $n_{s}/m^{*}$ at $T\to 0$ shows universal correlations with $T_{c}$. Similar strong correlations exist…
Adsorption of para-Hydrogen on the surface of graphite pre-plated with a single layer of atomic krypton is studied thoretically by means of Path Integral Ground State Monte Carlo simulations. We compute energetics and density profiles of…