相关论文: Enumerating low-frequency nonphononic vibrations i…
The ability to perform first-principles calculations of electronic and vibrational properties of two-dimensional heterostructures in a field-effect setup is crucial for the understanding and design of next-generation devices. We present…
Low-frequency Raman and inelastic neutron scattering of amorphous bis-phenol A polycarbonate is measured at low temperature, and compared. The vibrational density of states and light-vibration coupling coefficient are determined. The…
Amorphous packings prepared in the vicinity of the jamming transition play a central role in theoretical studies of the vibrational spectrum of glasses. Two mean-field theories predict that the vibrational density of states $g(\omega)$…
Several puzzling regularities concerning the low temperature excitations of glasses are quantitatively explained by quantizing domain wall motions of the random first order glass transition theory. The density of excitations agrees with…
Using Inelastic X-ray Scattering we studied the collective dynamics of the glassy alloy Ni$_{33}$Zr$_{67}$ in the first pseudo Brillouin zone, an energy-momentum region still unexplored in metallic glasses. We determine key properties such…
The acoustic vibrations of single monomers and dimers of gold nanoparticles were investigated by measuring for the first time their ultra-low frequency micro-Raman scattering. This experiment provides access not only to the frequency of the…
A simple model of harmonic vibrations in topologically disordered systems, such as glasses and supercooled liquids, is studied analytically by extending Euclidean Random Matrix Theory to include vector vibrations. Rather generally, it is…
The density of vibrational states $g(\omega)$ of an amorphous system is studied by using the random-matrix theory. Taking into account the most important correlations between elements of the random matrix of the system, equations for the…
The diatomic linear chain of masses coupled by harmonic springs is a textboook model for vibrational normal modes (phonons) in crystals. In addition to propagating acoustic and optic branches, this model is known to support a ``gap mode''…
Glasses are traditionally characterized by their rugged landscape of disordered low-energy states and their slow relaxation towards thermodynamic equilibrium. Far from equilibrium, dynamical forms of glassy behavior with anomalous algebraic…
Motivated by the concept of partial ergodicity, we present an alternative description of covalent and ionic glassy solids as statistical ensembles of crystalline local minima on the potential energy surface. We show analytically that the…
Understanding the effect of vibrations in optically active nano systems is crucial for successfully implementing applications in molecular-based electro-optical devices, quantum information communications, single photon sources, and…
Implications of reduction procedures applied to the low energy part of the vibrational density of states in glasses and supercooled liquids are considered by advancing a detailed comparison between the excess - over the Debye limit -…
Recent experiments on few-layer graphene structures have reported indirect signatures of anomalous Hall crystals (AHCs), but the need for a top gate to stabilize the phase precludes direct imaging of the emergent electronic lattice. This…
The existence of an acoustic plasmon in extrinsic (doped or gated) monolayer graphene was found recently in an {\it ab initio} calculation with the frozen lattice [M. Pisarra {\it et al.}, arXiv:1306.6273, 2013]. By the {\em fully dynamic}…
The boson peak (BP) is a universal feature in the Raman and inelastic scattering spectra of both disordered and crystalline materials. The current paradigm presents the boson peak as the result of a Ioffe-Regel crossover between ballistic…
We point out that the repeatedly reported glass-like properties of crystalline materials are not necessarily associated with localized (or quasilocalized) excitations. In real crystals, optical and short-wavelength acoustical vibrations…
The temperature dependence of the thermal conductivity of amorphous solids is markedly different from that of their crystalline counterparts, but exhibits universal behaviour. Sound attenuation is believed to be related to this universal…
The high-frequency excitations in glasses and supercooled liquids belong to the great mysteries of the physics of condensed matter. While the fast process, located at GHz-THz, can be interpreted as encaged molecular motion, the occurrence…
The optical properties of defects in solids produce rich physics, from gemstone coloration to single-photon emission for quantum networks. Essential to describing optical transitions is electron-phonon coupling, which can be predicted from…