Related papers: Liquid and solid phases of 3He on graphite
We revisited the phase diagram of the second layer of 4He on top of graphite using quantum Monte Carlo methods. Our aim was to explore the existence of the novel phases suggested recently in experimental works, and determine their…
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…
Adsorption of ortho-deuterium and para-hydrogen films on a graphite substrate, pre-plated with a single atomic layer of krypton, is studied theoretically by means of quantum Monte Carlo simulations at low temperature. Our model explicitly…
The discovery of fullerenes has stimulated extensive exploration of the resulting behavior of adsorbed films. Our study addresses the planar substrates graphene-fluoride (GF) and graphane (GH) in comparison to graphene. We present initial…
We calculated the phase diagram of the second layer of $para$-H$_2$ adsorbed on graphite using quantum Monte Carlo methods. The second layer shows an incommensurate triangular crystal structure. By using a symmetric wave function, that…
In this thesis we have used Quantum Monte Carlo techniques to study two systems that can be regarded as the archetype for neutral strongly interacting systems: 4He, and its fermionic counterpart 3He.More specifically, we have used the Path…
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…
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 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…
The phase diagrams of $^4$He adsorbed on the external surfaces of single armchair carbon nanotubes with radii in the range 3.42 -- 10.85 \AA \ are calculated using the diffusion Monte Carlo method. For nanotubes narrower than a (10,10) one,…
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…
The specific heat of a two-layer He-4 film adsorbed on a graphite substrate is estimated as a function of temperature by Quantum Monte Carlo simulations. The results are consistent with recent experimental observations, in that they broadly…
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…
The study of the adsorption phenomenon of helium began many decades ago with the discovery of graphite as a homogeneous substrate for investigation of physically adsorbed monolayer films. In particular, helium monoatomic layers on graphite…
We report results of diffusion Monte Carlo calculations for both $^4$He absorbed in a narrow single walled carbon nanotube (R = 3.42 \AA) and strictly one dimensional $^4$He. Inside the tube, the binding energy of liquid $^4$He is…
Using exact diagonalizations, we investigate the T=0 phase diagram of the Multi-Spin Exchange (MSE) model on the triangular lattice: we find a transition separating a ferromagnetic phase from a non-magnetic gapped Spin Liquid phase. Systems…
Fluid parts of the phase diagram of ${}^3$He -${}^4$He mixtures are obtained from a mean-field analysis of a suitable lattice gas model for binary liquid mixtures. The proposed model takes into account the continuous rotational symmetry…
We study by Quantum Monte Carlo simulations the phase diagram of lattice hard core bosons with nearest-neighbour repulsive interactions, in the presence of a super-lattice of adsorption sites. For a moderate adsorption strength, the system…
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 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…