Related papers: Local modes, phonons, and mass transport in solid …
Recent theoretical and experimental work on solid He-4 has focused on vacancies, or other lattice defects and whether these can form a Bose-Einstein condensate within the solid. The earliest suggestion that this could happen was based on…
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…
In this work we investigate implications of the quantum nature of bcc $^{4}$% He. We show that it is a unique solid phase with both a lattice structure and an Off-Diagonal Long Range Order of coherently oscillating local electric dipole…
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…
We propose a new way to treat nuclear magnetism of solid $^{3}$He. We argue that the magnetic interaction arises indirectly as a consequence of correlated zero-point motion of the ions. This motion lowers the energy of the ground state, and…
In the paper we apply asymptotic technique based on the method of stationary phase and obtain the approximate analytical description of thermal motions caused by a source on an isotopic defect of an arbitrary mass in a 1D harmonic crystal.…
We propose a new way to treat the ordering of nuclear magnetism of solid $^{3}$He. We argue that the magnetic interaction arises indirectly as a consequence of correlated zero-point motion of the ions. This motion lowers the energy of the…
We study the localization properties of normal modes in harmonic chains with mass and spring weak disorder. Using a perturbative approach, an expression for the localization length is obtained, which is valid for arbitrary correlations of…
The application of the locally harmonic approximation to large scale collective motion is briefly reviewed. Particular emphasis is paid to issues which might be useful in the more general context, or which are specific to our treatment,…
This work presents recent the progress in the development of the Concurrent Atomistic-Continuum (CAC) method for coarse-grained space- and time-resolved atomistic simulations of phonon transport. Application examples, including heat pulses…
Using Path Integral Monte Carlo and the Maximum Entropy method, we calculate the dynamic structure factor of solid $^4$He in the bcc phase at a finite temperature of T = 1.6 K and a molar volume of 21 cm$^3$. Both the single-phonon…
Point defects play a crucial role in crystalline materials as they do not only impact the thermodynamic properties but are also central to kinetic processes. While they are necessary in thermodynamic equilibrium spontaneous defect formation…
Vibrational heat transport in molecular junctions is a central issue in different contemporary research areas like Chemistry, material science, mechanical engineering, thermoelectrics and power generation. Our model system consists of a…
A resolvent formalism is applied to the problem of inelastic scattering of an electron linearly coupled to a set of phonon modes. It is shown how the many phonon mode coupling and excitation can be reduced to a single phonon mode…
Studying charge transport in models with nonlocal carrier--phonon interaction is difficult because it requires finite-temperature real-time correlation functions of mixed carrier--phonon operators. Focusing on models with discrete undamped…
Ionic transport in conventional ionic solids is generally considered to proceed via independent diffusion events or "hops''. This assumption leads to well-known Arrhenius expressions for transport coefficients, and is equivalent to assuming…
A vibrational model of transport properties of dense fluids assumes that solid-like oscillations of atoms around their temporary equilibrium positions dominate the dynamical picture. The temporary equilibrium positions of atoms do not form…
Coherent phonons describe the collective, ultrafast motion of atoms and play a central role in light-induced structural dynamics. Here, we employ terahertz scanning tunneling microscopy (THz-STM) to excite and detect coherent phonons in…
The temperature and volume dependences of the thermal conductivity of solid Kr(1-x)Xe(x)solution are analyzed within the model in which heat is transferred by mobile low-frequency phonons; above the phonon mobility edge this is done by…
We report neutron scattering measurements of the phonons in bcc solid 4He. In general, only 3 accoustic phonon branches should exist in a monoatomic cubic crystal. In addition to these phonon branches, we found a new ''optic-like'' mode…