Related papers: Zero-point Divacancy Concentration in the Shadow W…
We present an approach to studying optical band gaps in real solids in which quantum Monte Carlo methods allow for the application of a rigorous variational principle to both ground and excited state wave functions. In tests that include…
Dissipationless flows in single-component superfluids have a significant degree of universality. In He4, the dissipationless mass flow occurs with a superfluid velocity determined by the gradient of the superfluid phase. However, in…
We calculate the four point correlation function for scalar perturbations in the canonical model of slow-roll inflation. We work in the leading slow-roll approximation where the calculation can be done in de Sitter space. Our calculation…
A simple phenomenological model is developed for the recent torsional oscillator experiments on solid $^4$He. Within this model, for a homogeneous sample there is a specific quantitative relation between the change in the oscillator's…
High entropy oxides (HEOs) are single phase solid solutions consisting of 5 or more cations in approximately equiatomic proportions. In this study, we show reversible control of optical properties in a rare-earth (RE) based…
Frequency shifts and dissipations of a compound torsional oscillator induced by solid $^4$He samples containing $^3$He impurity concentrations ($x_3$ = 0.3, 3, 6, 12 and 25 in units of 10$^{-6}$) have been measured at two resonant mode…
We investigate the interactions between two drops in a heated environment and analyze the effect of evaporation on bouncing, coalescence and reflexive separation phenomena. A reliable mass transfer model is incorporated in a coupled…
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…
Defects in silicon carbide are of intense and increasing interest for quantum-based applications due to this material's properties and technological maturity. We calculate the multi-particle symmetry adapted wave functions of the negatively…
Role of different continuum components in the weakly bound nucleus 6He is studied by coupling unbound spd-waves of 5He by using simple pairing contact-delta interaction. The results show that 6He ground state $0^+$ displays collective…
The mean square atomic displacement in hcp-phase solid He-4 has been measured in crystals with a molar volume of 21.3 cm^3. It is temperature independent from 1 K to 140 mK, with no evidence for an anomaly in the vicinity of the proposed…
We examine the effect of vacancies on the phase behavior and structure of systems consisting of hard cubes using event-driven molecular dynamics and Monte Carlo simulations. We find a first-order phase transition between a fluid and a…
Use of amorphous silicon ($a$-Si) and hydrogenated amorphous silicon ($a$-Si:H) in photovoltaics has been limited by light-induced degradation (the Staebler-Wronski effect) and low hole mobilities, and voids have been implicated in both…
Superfluidity, liquid flow without friction, is familiar in helium. The first evidence for "supersolidity", its analogue in quantum solids, came from recent torsional oscillator (TO) measurements involving 4-He. At temperatures below 200…
This paper establishes the spectral stability of monotone traveling front solutions for reaction-diffusion equations where the reaction function is of Nagumo (or bistable) type and with diffusivities which are density dependent and…
We present a continuum theory of self-propelled particles, without alignment interactions, in a momentum-conserving solvent. To address phase separation we introduce a scalar concentration field $\phi$ with advective-diffusive dynamics.…
A novel density functional, which accounts correctly for the equation of state, the static response function and the phonon-roton dispersion in bulk liquid helium, is used to predict static and dynamic properties of helium droplets. The…
In the present work, we report a detailed density functional theory calculation on polymorphic InVO$_4$ phases by means of projector augmented wave method. The computed first-order structural phase transformation from orthorhombic…
By using the diffusion Monte Carlo method, we obtained the full phase diagram of $^3$He on top of graphite preplated with a solid layer of $^4$He. All the $^4$He atoms of the substrate were explicitly considered and allowed to move during…
The temperature dependence of the one-body density matrix in 4He crystals presenting vacancies is computed with Path Integral Monte Carlo. The main purpose of this study is to estimate the onset temperature T_0 of Bose-Einstein condensation…