Related papers: Universality of phonon transport in surface-roughn…
The ultralow thermal conductivity $\kappa$ observed experimentally in intentionally roughened silicon nanowires (SiNWs) is reproduced in phonon Monte Carlo simulations with exponentially correlated real-space rough surfaces similar to…
We present a novel approach for computing the surface roughness-limited thermal conductivity of silicon nanowires with diameter D < 100 nm. A frequency-dependent phonon scattering rate is computed from perturbation theory and related to a…
We explain the reduction of the thermal conductance below the predicted universal value observed by Schwab et al. in terms of the scattering of thermal phonons off surface roughness using a scalar model for the elastic waves. Our analysis…
Experimental observation of highly reduced thermal conductivity in surface-roughness dominated silicon nanowires have generated renewed interest in low-dimensional thermoelectric devices. Using a previous work where the scattering of…
The effect of phonon scattering by surface roughness on the thermal conductance in mesoscopic systems at low temperatures is calculated using full elasticity theory. The low frequency behavior of the scattering shows novel power law…
The effect of sample size and surface roughness on the phonon thermal conductivity $\kappa_p$ of Nd$_2$CuO$_4$ single crystals was studied down to 50 mK. At 0.5 K, $\kappa_p$ is proportional to $\sqrt{A}$, where $A$ is the cross-sectional…
We measure the thermal conductivity ($\kappa$) of individual InAs nanowires (NWs), and find that it is 3 orders of magnitude smaller than the bulk value in the temperature range of 10 to 50 K. We argue that the low $\kappa$ arises from the…
Based on the Landauer formalism, we demonstrate that the thermal conductance due to the propagation of surface phonon-polaritons along a polar nanowire is independent of the material characteristics and is given by Pi^2kB^2T/3h. The giant…
Studies of possible localization of phonons in nanomaterials have gained importance in recent years in the context of thermoelectricity where phonon-localization can reduce thermal conductivity, thereby improving the efficiency of…
We present analytical model and molecular dynamics simulations of phonon heat transport in nanowires and nanoribbons with anharmonic lattices and dynamically rough surfaces and edges. In agreement with recent experiments on heat transport…
We have investigated the effect on phonon energy transport in mesoscopic systems and the reduction in the thermal conductance in the quantum limit due to phonon scattering by surface roughness using full 3-dimensional elasticity theory for…
The wave property of phonons is employed to explore the thermal transport across a finite periodic array of nano-scatterers such as circular and triangular holes. As thermal phonons are generated in all directions, we study their…
We present an analysis of acoustic phonon propagation through long, free-standing, insulating wires with rough surfaces. Due to a crossover from ballistic propagation of the lowest-frequency phonon mode at $\omega <\omega _{1}=\pi c/W$ to a…
Thermal transport properties of amorphous materials at low temperatures are governed by the interaction between phonons and localized excitations referred to as tunneling two level systems (TLS). The temperature variation of the thermal…
Based on first-principles calculations and full iterative solution of the linearized Boltzmann-Peierls transport equation for phonons within three-phonon scattering framework, we characterize the lattice thermal conductivities $\kappa$ of…
Suppressing phonon propagation in nanowires is an essential goal towards achieving efficient thermoelectric devices. Recent experiments have shown unambiguously that surface roughness is a key factor that can reduce the thermal conductivity…
The thermal conductivity of low-dimensional materials and graphene nanoribbons in particular, is limited by the strength of line-edge-roughness scattering. One way to characterize the roughness strength is the dependency of the thermal…
Scattering of phonons at boundaries of a crystal (grains, surfaces, or solid/solid interfaces) is characterized by the phonon wavelength, the angle of incidence, and the interface roughness, as historically evaluated using a specularity…
Structural defects in one-dimensional heat conductors couple longitudinal (stretching) and transverse (bending) vibrations. This coupling results in the scattering of longitudinal phonons to transverse phonons and backwards. We show that…
We investigate the phonon thermal conductivity $\kappa_{\mathrm{ph}}$ of doped $\rm La_2CuO_4$ based on out-of-plane thermal conductivity measurements. When room temperature is approached the temperature dependence of $\kappa_{\mathrm{ph}}$…