相关论文: Four-dimensional Vibrational Spectroscopy for Nano…
Propagating atomic vibrational waves, phonons, rule important thermal, mechanical, optoelectronic and transport characteristics of materials. Thus the knowledge of phonon dispersion, namely the dependence of vibrational energy on momentum…
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…
Recent developments in experiments with vibrational electron energy loss spectroscopy (EELS) have revealed spectral shape variations at spatial resolutions down to sub-atomic scale. Interpretation in terms of local phonon density of states…
We present a comprehensive first-principles investigation of the structural, electronic, and vibrational properties of four layered boron nitride (BN) polymorphs--AA-stacked ($e$-BN), AA$^\prime$-stacked ($h$-BN), ABC-stacked ($r$-BN), and…
Van der Waals (vdW) materials exhibit intriguing structural, electronic and photonic properties. Electron Energy Loss Spectroscopy (EELS) within Scanning Transmission Electron Microscope (STEM) allows for nanoscale mapping of such…
We introduce a novel method for the simulation of the impact scattering in vibrational scanning transmission electron microscopy electron energy loss spectroscopy (STEM-EELS) simulations. The phonon-loss process is modeled by a combination…
While phonons and their related properties have been studied comprehensively in bulk materials, a thorough understanding of surface phonons for nanoscale objects remains elusive. Infra-red imaging methods with photons or electrons exist,…
High energy electron beams can now be routinely focused to 1-2 {\AA} and offer the ability to obtain vibrational information from materials using monochromated electron energy-loss spectroscopy (EELS) in a scanning transmission electron…
Raman spectroscopy has become an essential technique to characterize and investigate graphene and many other two-dimensional materials. However, there still lacks consensus on the Raman signature and phonon dispersion of atomically thin…
A recent study [Rosati, Dolcini, and Rossi, Appl. Phys. Lett. 106, 243101 (2015)] has predicted that, while in semiconducting single-walled carbon nanotubes (SWNTs) an electronic wave packet experiences the typical spatial diffusion of…
Hyperbolic phonon polaritons (HPhPs) in hexagonal boron nitride (hBN) enable the direct manipulation of mid-infrared light at nanometer scales, many orders of magnitude below the free-space light wavelength. High resolution monochromated…
Phonon dispersion is widely used to elucidate the vibrational properties of materials. As an emerging technique, momentum-resolved vibrational spectroscopy in scanning transmission electron microscopy (STEM) offers an unparalleled approach…
We theoretically investigated electron energy loss spectroscopy (EELS) of ultraviolet surface plasmon modes in aluminum nanodisks. Using full-wave simulations, we studied the impact of diameter on the resonant modes of the nanodisks. We…
We provide a theoretical framework for the prediction and interpretation of momentum dependent phonon spectra due to coherent inelastic scattering of electrons. We complete the approach with first principles lattice dynamics using periodic…
Nanoscale defects such as dislocations, have a significant impact on the phonon thermal transport properties in non-metallic materials. To unravel these effects, understanding of defect phonon modes is essential. Herein, at the atomic…
Vibrations in materials and nanostructures at sufficiently high temperatures result in anharmonic atomic displacements, which leads to new phenomena such as thermal expansion and multiphonon scattering processes, with a profound impact on…
We present a detailed study of the vibrational properties of Single Wall Carbon Nanotubes (SWNTs). The phonon dispersions of SWNTs are strongly shaped by the effects of electron-phonon coupling. We analyze the separate contributions of…
Transmission electron microscopy and spectroscopy currently enable the acquisition of spatially resolved spectral information from a specimen by focusing electron beams down to a sub-Angstrom spot and then analyzing the energy of the…
Plasmons dispersion and nonvertical interband transitions in Bi2Se3 single crystals were investigated by electron energy-loss spectroscopy in conjunction with (scanning) transmission electron microscopy, (S)TEM-EELS. Both volume plasmons…
High bias electrical transport characteristics of freely suspended metallic single-walled carbon nanotubes (SWNTs) are investigated at 250-400K in vacuum and various gases. Self-heating is exploited to examine the temperature dependence of…