Related papers: Electron-phonon and spin-phonon coupling in NaV$_{…
The interplay of electron-electron and electron-phonon interactions is studied analytically in the Kondo regime. A Holstein electron-phonon coupling is shown to produce a weakening of the gate voltage dependence of the Kondo temperature and…
We study the electronic states and the superconductivity in the two-dimensional 16-band d-p model coupled with A1g, B1g and Eg local phonons and obtain the rich phase diagram including the magnetic, charge and orbital ordered phases on the…
Polarized Raman spectra of the calcium vanadium oxide bronze beta-Ca0.33V2O5 are measured in the temperature range between 300 K and 20 K. The charge ordering phase transition at about 150 K is characterized by the appearance of the new…
Spin-charge-lattice coupling mediated by multi-magnon processes is demonstrated in multiferroic BiFeO3. Experimental evidence of two and three magnons excitations as well as multimagnon coupling at electronic energy scales and high…
The electron-phonon interaction is of central importance for the electrical and thermal properties of solids, and its influence on superconductivity, colossal magnetoresistance, and other many-body phenomena in correlated-electron materials…
We consider electron(hole)-phonon coupling in crystalline organic semiconductors, using naphthalene for our case study. Employing a first-principles approach, we compute the changes in the self-consistent Kohn-Sham potential corresponding…
The charge ordering transition in the layer compound NaV2O5 is studied by means of exact diagonalization methods for finite systems. The 2-leg ladders of the V-Trellis lattice are associated with one spin variable of the vanadium…
We consider electron pairing in a two-dimensional thermally disordered itinerant anti-ferromagnet. It is shown that transverse spin fluctuations in such a state can give rise to superconductivity with a sizeable critical temperature $T_c$.…
Recent studies exposed many remarkable properties of layered cobaltates NaxCoO2. Surprisingly, many-body effects have been found to increase at sodium-rich compositions of NaxCoO2 where one expects a simple, nearly free motion of the dilute…
The leading superconducting instabilities of the two-dimensional extended repulsive one-band Hubbard model within spin-fluctuation pairing theory depend sensitively on electron density, band and interaction parameters. We map out the phase…
Ultrafast optical pump - optical probe and optical pump - terahertz probe spectroscopy were performed on vanadium dioxide (VO2) and vanadium sesquioxide (V2O3) thin films over a wide temperature range. A comparison of the experimental data…
We study theoretically and experimentally the dependence of the electron-phonon interaction in Na$_x$CoO$_2$ on the sodium concentration $x$. For the two oxygen phonon modes found in Raman experiments, $A_{1g}$ and $E_{1g}$, we calculate…
The application of weak electric fields (<~ 100 V/cm) is found to dramatically enhance the lattice thermal conductivity of the antiferromagnetic (AF) insulator CaMnO(3) over a broad range of temperature about the Neel ordering point (125…
The coupling of electrons and phonons is governed wisely by the symmetry properties of the crystal structures. In particular, for two-dimensional (2D) systems, it has been suggested that the electrons do not couple to phonons with pure…
In order to explore how superconductivity arises when charge fluctuations and spin fluctuations coexist, we have obtained a phase diagram against the off-site repulsion V and band filling n for the extended, repulsive Hubbard model on the…
We study the interplay between charge and spin ordering in electronic liquid crystalline states with a particular emphasis on fluctuating spin stripe phenomena observed in recent neutron scattering experiments\cite{Hinkov2008, Haug2009}.…
The influence of spin and charge fluctuations on spectra of the two-dimensional fermionic Hubbard model is considered using the strong coupling diagram technique. Infinite sequences of diagrams containing ladder inserts, which describe the…
We show that the proposed zig--zag charge--ordering model for alpha'--NaV2O5 is incompatible with a single transition that induces both charge--ordering and spin gap. We introduce a two--band model for alpha'--NaV2O5 within which the…
Superconductivity without phonons has been proposed for strongly correlated electron materials that are tuned close to a zero-temperature magnetic instability of itinerant charge carriers. Near this boundary, quantum fluctuations of…
UV Raman scattering studies show longitudinal optical (LO) mode up to 4th order in wurtzite GaN nanowire system. Frohlich interaction of electron with the long range electrostatic field of ionic bonded GaN gives rise to enhancement in LO…