Related papers: Phonon localization in surface-roughness dominated…
We study the effect of confinement on the phonon properties of ultra-narrow silicon nanowires of side sizes of 1-10nm . We use the modified valence force field method to compute the phononic dispersion, and extract the density of states,…
The thermal properties of solids under nanoscale confinement are currently not understood at the atomic level. Recent numerical studies have highlighted the presence of a minimum in the thermal conductivity as a function of thickness for…
The world communicates to our senses of vision, hearing and touch in the language of waves, as the light, sound, and even heat essentially consist of microscopic vibrations of different media. The wave nature of light and sound has been…
Nanostructuring materials at small scales enables control over their physical properties, revealing behaviors not observed at larger dimensions. This strategy is particularly effective in two-dimensional (2D) materials, where surface…
Engineering phonon transport in physical systems is a subject of interest in the study of materials and plays a crucial role in controlling energy and heat transfer. Of particular interest are non-reciprocal phononic systems, which in…
Phonons are responsible for limiting both the electron mobility and the spin relaxation time in solids and provide a mechanism for thermal transport. In view of a possible transistor function as well as spintronics applications in graphene…
Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. Modification of acoustic phonon spectrum in structures with periodically modulated elastic constant or mass density -…
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…
The thermal conductance by phonons of a quasi-one-dimensional solid with isotope or defect scattering is studied using the Landauer formalism for thermal transport. The conductance shows a crossover from localized to Ohmic behavior, just as…
We present a review of the phonon thermal conductivity of segmented nanowires focusing on theoretical results for Si and Si/Ge structures with the constant and periodically modulated cross-sections. We describe the use of the face-centered…
A comprehensive rational thermal material design paradigm requires the ability to reduce and enhance the thermal conductivities of nanomaterials. In contrast to the existing ability to reduce the thermal conductivity, methods that allow to…
Interfaces play an essential role in phonon-mediated heat conduction in solids, impacting applications ranging from thermoelectric waste heat recovery to heat dissipation in electronics. From the microscopic perspective, interfacial phonon…
The electrical conductivity of a macroscopic assembly of nanomaterials is determined through a complex interplay of electronic transport within and between constituent nano-objects. Phonons play dual roles in this situation: their increased…
The photoacoustic method with piezoelectric detection for the simultaneous evaluation of the thermophysical properties is proposed. The approach is based on the settling of an additional heat sink for redistribution of heat fluxes deposited…
Surface phonon polaritons hold much potential for subwavelength control and manipulation of light at the infrared to terahertz wavelengths. Here, aided by monochromatic scanning transmission electron microscopy - electron energy loss…
We solve the problem of polaron localization on an attractive impurity by means of direct-space Diagrammatic Monte Carlo implemented for the system in the thermodynamic limit. In particular we determine the ground state phase diagram in…
In this work, we investigate dielectric materials for thermoreflectance-based thermal sensing by extracting key optical parameters using temperature-dependent spectroscopic ellipsometry in the mid-infrared regime. Leveraging optical phonon…
Understanding the electronic and phononic transport properties of junctions consisting of a scattering region such as a nanoscale matters or molecules connected to two or more electrodes is the central basis for future nano and molecular…
This review summarizes recent studies of thermal transport in nanoscaled semiconductors. Different from bulk materials, new physics and novel thermal properties arise in low dimensional nanostructures, such as the abnormal heat conduction,…
Heat transport in bulk materials is well described using the Debye theory of 3D vibrational modes (phonons) and the acoustic match model. However, in cryogenic nanodevices, phonon wavelengths exceed device dimensions, leading to confinement…