Related papers: Interaction of phonons at superfluid helium-solid …
The Boltzmann transport equation for phonons is recast directly in terms of the heat-flux by means of iteration followed by truncation at the second order in the spherical harmonic expansion of the distribution function. This procedure…
Detailed understanding of vibrational heat transfer mechanisms between solids is essential for the efficient thermal engineering and control of nanomaterials. We investigate the frequency dependence of anharmonic scattering and interfacial…
The dynamics of vortices in a superfluid film at the absolute zero of temperature is studied. The quantum-mechanical, i.e., ``first-quantized'' description is compared to a recently proposed quantum-field-theoretic, i.e.,…
Superfluid helium consists of two inter-penetrating fluids, a viscous normal fluid and an inviscid superfluid, coupled by a mutual friction. We develop a two-fluid shell model to study superfluid turbulence. We investigate the energy…
An experiment is proposed to test a previously developed theory of the hydrodynamics of a nonequilibrium heat current-induced superfluid-normal interface. It is shown that the interfacial ``trapped'' second sound mode predicted by the…
Multiphonon processes in a model quantum dot (QD) containing two electronic states and several optical phonon modes are considered taking into account both intra- and inter-level terms. The Hamiltonian is exactly diagonalized including a…
We recently proposed a high-pressure and high-temperature P-62m-symmetry polymorph for CaF2 on the basis of ab-initio random structure searching and density-functional theory calculations [Phys. Rev. B 95, 054118 (2017)]. We revisit this…
In studies of dynamical systems, helium atoms scatter coherently from an ensemble of adsorbates as they diffuse on the surface. The results give information on the co-operative behaviour of interacting adsorbates and thus include the…
The traditional picture of heat transfer in solids by atomic vibrations, also known as phonons, involves phonons scattering with each other like gas particles and is commonly referred to as the phonon gas model (PGM). This physical picture…
We report an experimental investigation of the electric response of superfluid helium. Our results confirm the presence of electric potential that appears at the relative oscillatory motion of normal fluid and superfluid components in…
In this article we discuss the analogy between superfluids and a spinning thick cosmic string. We use the geometrical approach to obtain the geometrical phases for a phonon in the presence of a vortex. We use loop variables for a geometric…
We develop a microscopic model of mutual friction represented by the dissipative dynamics of a normal fluid flow which interacts with the helical normal modes of vortices comprising a lattice in thermal equilibrium. Such vortices are…
Superfluidity is a macroscopic quantum phenomenon, which shows up below a critical temperature and leads to a peculiar behavior of matter, with frictionless flow, the formation of quantized vortices, and the quenching of the moment of…
The thermodynamics of liquids and supercritical fluids is notorious for eluding a general theory, as can be done for crystalline solids on the basis of phonons and crystal symmetry. The extension of solid state notions such as…
The influence of a fluid-fluid interface on self-phoresis of chemically active, axially symmetric, spherical colloids is analyzed. Distinct from the studies of self-phoresis for colloids trapped at fluid interfaces or in the vicinity of…
We present a theory for the formation of a mesa shaped phonon pulse in superfluid $^4$He. Starting from the hydrodynamic equations of superfluid helium, we obtain the system of equations which describe the evolution of strongly anisotropic…
The Hamiltonian of electrons interacting with interface phonons in three-barrier resonant tunneling structure is established using the first principles within the models of effective mass and polarization continuum. Using the Green's…
Traditional theories of interfacial heat transfer by atomic vibrations, also known as phonons, do not explain how vibrational mode interactions contribute to interface conductance. Traditional methods also use the concept of phonons as…
The breakdown of translational symmetry at heterointerfaces leads to the emergence of new phonon modes localized near the interface. These interface phonons play an essential role in thermal/electrical transport properties in devices…
Describing electron-phonon interactions in a solid requires knowledge of the electron-phonon matrix elements in the Hamiltonian. State-of-the-art first-principles calculations for the electron-phonon interaction are limited to the…