Effective inter-band coupling in MgB 2 due to anharmonic phonons. Abstract We investigate the origin of the inter-band coupling in M gB 2 by focusing on its unusual phononic features, namely, the strong anharmonicity of the phonons and the presence of both linear and quadratic electron-phonon interactions of the Su-Schrieffer-Heeger (SSH) type. The bare electronic Hamil-tonian has two bands wit...

Inelastic electron process that leads to vibrational excitation has attracted much attention of since the conductivity of molecules bridging the electrodes is found to be strongly affected when they are vibrationally excited [1]. Considering that the conduction electrons passes through the electronic state crossing the Fermi level or hopping through the HOMO or LUMO state of the molecule, the e...

We study the influence of the phonon spectrum on polaron formation and show that three self-trapping regimes can occur. If the lattice and the electronlattice Hamiltonians are dominated by the same type of phonons, the selftrapping transition is smooth. If there is an imbalance, the transition can either be abrupt or completely eliminated. The binding energies are larger in the case of imbalanc...

We consider a two-dimensional layer of dipolar particles in the regime of strong dipole moments. Here we can describe the system using classical methods and determine the crystal structure that minimizes the total energy. The dipoles are assumed to be aligned by an external field and we consider different orientations of the dipolar moments with respect to the two-dimensional plane of motion. W...

Quasi-one-dimensional Peierls systems with quantum and thermal lattice fluctuations can be modeled by a Dirac-type equation with a Gaussiancorrelated off-diagonal disorder. A powerful new method gives the exact disorder-averaged Green function used to compute the optical conductivity. The strong subgap tail of the conductivity has a universal scaling form. The frequency and temperature dependen...

Si Nanowires (NWs) were studied by Raman microspectroscopy. The Raman spectrum of the NWs reveals important thermal effects, which broaden and shift the one phonon Raman bands. The low thermal conductivity of the NWs and the low thermal dissipation are responsible for the temperature enhancement in the NW under the excitation with the laser beam. We have modeled, using finite element methods, t...

In this study, Bio-based carbon nanotubes (CNTs) have received considerable research attention due to their comparative advantages of high level stability, simplistic use, low toxicity and overall environmental friendliness. New potentials for improvement in heat transfer applications are presented due to their high aspect ratio, high thermal conductivity and special surface area. Phonons have ...

Wavelength derivative and thermomodulated reflectivity spectra of gallium telluride in the UV-visible range (1.0-6.0 eV), and infrared (15-80 meV) derivative absorption spectra of gallium sulphide and selenide at room temperature are presented and interpreted as due to threedimensional or two-dimensional critical points and one or two phonons absorption respectively A new model for the complex ...