Related papers: Specific heat of thin $^4$He films on graphite
Path-integral Monte Carlo calculations have been performed to study the $^4$He adsorption on $\gamma$-graphyne, a planar network of benzene rings connected by acetylene bonds. Assuming the $^4$He-substrate interaction described by a…
Phase transitions, as the condensation of a gas to a liquid, are often revealed by a discontinuous behavior of thermodynamic quantities. For liquid Helium, for example, a divergence of the specific heat signals the transition from the…
Helium is recognized as a model system for the study of phase transitions. Of particular interest is the superfluid phase in two dimensions. We report measurements on superfluid helium films adsorbed on the surface of a suspended carbon…
We present the first large-scale molecular dynamics simulations of hexane on graphite that completely reproduces all experimental features of the melting transition. The canonical ensemble simulations required and used the most realistic…
A recent claim of possible superfluid behaviour of parahydrogen films intercalated within a crystalline matrix of Na atoms is examined. Quantum Monte Carlo simulations at finite temperature yield strong numerical evidence that the system…
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…
We investigate the first layer of helium adsorbed on graphite with path-integral Monte Carlo, examining the role of substrate corrugations on the phase diagram. When no corrugations are present, the equilibrium state of the system is a…
We demonstrate the temperature-mediated and completely reversible process of desorption-readsorption of water on a few layers of epitaxial graphene on a 4H-SiC(0001) substrate. We show that under ambient conditions water forms solid…
We review experimental results, from transport to magnetization measurements, on different graphite samples, from bulk oriented graphite, thin graphite films to transmission electron microscope lamellae, that indicate the existence of…
We calculate the finite temperature compressibility for two-dimensional semiconductor systems, monolayer graphene, and bilayer graphene within the Hartree-Fock approximation. We find that the calculated temperature dependent compressibility…
The satisfactory explanation of abnormal electromagnetics in thin graphite-like carbon films till now is absent. The most comprehensible explanation may be the high-temperature superconductivity (HTSC). Times of spasmodic switching of…
We present an approach to the melting of graphene based on nucleation theory for a first order phase transition from the 2D solid to the 3D liquid via an intermediate quasi-2D liquid. The applicability of nucleation theory, supported by the…
We present the application of a fast quasi-adiabatic continuous method to the measurement of specific heat at 4He temperatures, which can be used for the study of a wide range of materials. The technique can be performed in the same…
Wavelike thermal transport in solids, referred to as second sound, has until now been an exotic phenomenon limited to a handful of materials at low temperatures. This has restricted interest in its occurrence and in its potential…
We present a zero-temperature quantum Monte Carlo calculation of liquid $^4$He immersed in an array of confining potentials. These external potentials are centered in the lattice sites of a fcc solid geometry and, by modifying their well…
We show theoretically that the second layer of 3He adsorbed on graphite and solidified at 4/7 of the first-layer density is close to the fluid-solid boundary with substantial density fluctuations on the third layer. The solid shows a…
The heat capacity of solids at intermediate-to-high temperatures is of fundamental importance to several fields ranging from geology to material science. It depends on a variety of factors, with anharmonicity and, ultimately, melting…
We theoretically investigate ultrafast and nonlinear optical properties of graphite thin films based on first-principles time-dependent density functional theory. We first calculate electron dynamics in a unit cell of graphite under a…
Measurements of Casimir effects in $^4$He films in the vicinity of the bulk superfluid transition temperature $T_\lambda$ have been carried out, where changes in the film thickness and the superfluid density are both monitored as a function…
The compressibility of solid helium (3He and 4He) in the hcp and fcc phases has been studied by path-integral Monte Carlo. Simulations were carried out in both canonical (NVT) and isothermal-isobaric (NPT) ensembles at temperatures between…