Related papers: Polymorphism, phonon dynamics and carrier-phonon c…
In this paper we elucidate the optical response resulting from the interplay of charge distribution (ionicity) and Peierls instability (dimerization) in the neutral-ionic, ferroelectric phase transition of tetrathiafulvalene-chloranil…
We combine polarization-resolved low frequency Raman microscopy and dispersion-corrected density-functional calculations (DFT-D3) to study polymorph-dependent lattice vibrations in coronene, a model molecular system for nanographenes and…
For an fcc crystal with central force interactions and separately for a scalar model on a square lattice, we compute exactly the phonon transmission coefficient $T(\omega)$ through a disordered planar interface between two identical semi -…
The structural and electronic properties of a single pentacene molecule and a pentacene molecular crystal, an organic semiconductor, are examined by a first-principles method based on the generalized gradient approximation of density…
The phase transition to the state of a phonon gas with pairwise correlations of interacting phonons with opposite momenta is studies. A method for describing such phonon systems within the framework of the self-consistent field model is…
The intermolecular lattice vibrations in small-molecule organic semiconductors have a strong impact on their functional properties. Existing models treat the lattice vibrations within the harmonic approximation. In this work, we use…
Structural modifications in InP(111) due to 1.5 MeV implantation of Sb have been characterized using first order and second order Raman spectroscopy. With both Longitudinal Optical (LO) and Transverse Optical (TO) modes allowed for…
The quantum phase transition between a repulsive Luttinger liquid and an insulating Peierls state is studied in the framework of the one-dimensional spinless Holstein model. We focus on the adiabatic regime but include the full quantum…
We use variable-temperature x-ray thermal diffuse scattering and inelastic scattering to investigate the lattice dynamics in single crystals of multiferroic CaMn7O12 which undergo a series of orbital and magnetic transitions at low…
In the quest for stable 2D arsenic phases, four different structures have been recently claimed to be stable. We show that, due to phonon contributions, the relative stability of those structures differs from previous reports and depends…
A study of charged particle and quasi-particle anharmonic lattice excitations in a meta-stable crystal of layered structure at high temperature has shown that a mobile lattice excitation called a quodon can bind securely to a hole or…
Phonon quasi-particles have been monumental in microscopically understanding thermodynamics and transport properties in condensed matter for decades. Phonons have one-to-one correspondence with harmonic eigenstates and their energies are…
A complex approach phonon quantum discrete model (PQDM) was developed to describe dynamics, kinetics and statistics of phonons in carbon nanostructures with zero-chirality of both zig-zag and armchair geometry. The model allows include into…
A fundamental understanding of phonon transport in stanene is crucial to predict the thermal performance in potential stanene-based devices. By combining first-principle calculation and phonon Boltzmann transport equation, we obtain the…
During phase transitions certain properties of a material change, such as composition field and lattice-symmetry distortions. These changes are typically coupled, and affect the microstructures that form in materials. Here, we propose a 2D…
We report on the dynamics of coherent phonons in semimetal 1T'-MoTe2 using femtosecond pump-probe spectroscopy. On an ultrafast sub-picosecond time scale at room temperature, a low frequency and long-lifetime shear phonon mode was observed…
On the basis of the self-consistent phonon theory and the special displacement method, we develop an approach for the treatment of anharmonicity in solids. We show that this approach enables the efficient calculation of…
Topological phase transitions occur when the electronic bands change their topological properties, typically featuring the closing of the bandgap. While the influence of topological phase transitions on electronic and optical properties has…
Understanding heat transport in organic semiconductors is of fundamental and practical relevance. Therefore, we study the lattice thermal conductivities of a series of (oligo)acenes, where an increasing number of rings per molecule leads to…
PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this…