scholarly journals Phonon density of states, anharmonicity, electron-phonon coupling, and possible multigap superconductivity in the clathrate superconductorsBa8Si46andBa24Si100: Factors behind large difference inTc

2008 ◽  
Vol 77 (22) ◽  
Author(s):  
Rolf Lortz ◽  
Romain Viennois ◽  
Alexander Petrovic ◽  
Yuxing Wang ◽  
Pierre Toulemonde ◽  
...  
Keyword(s):  
Density Of States ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

Anharmonic phonon–electron effects on phonon density of states in La2−xSrxCuO4

2015 ◽  
Vol 29 (29) ◽  
pp. 1550177 ◽  
Author(s):  
Vinod Ashokan ◽  
B. D. Indu
Keyword(s):  
Density Of States ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Phonon Coupling ◽  
Perturbative Approach ◽  
Electron Phonon Coupling ◽  
Double Time ◽  
Electron Effects

In the present work, the phonon density of states (PDOS) for [Formula: see text] crystal is investigated by using the double time thermodynamic Green’s function method via a non-perturbative approach. A newly formulated Hamiltonian is considered for the lattice dynamics of phonon, which includes the effects of electron–phonon interactions, lattice anharmonicities and the interacting isotopic impurities. The automated emergence of pairons and [Formula: see text] wave pairing mechanism appears as a salient features of the theory. The PDOS is found to be dependent on temperature, impurity concentration, electron–phonon coupling coefficient and renormalized frequencies, and the numerical investigations on PDOS exhibits fairly good agreements with the inelastic neutron scattering experimental observations.

scholarly journals Phonon Spectra of Small Colloidal II-VI Semiconductor Nanocrystals

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Volodymyr Dzhagan ◽  
Mykhailo Valakh ◽  
Nikolai Mel'nik ◽  
Olexandra Rayevska ◽  
Irina Lokteva ◽  
...  
Keyword(s):  
Semiconductor Nanocrystals ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Phonon Coupling ◽  
Phonon Modes ◽  
Phonon Spectra ◽  
Electron Phonon Coupling ◽  
Unified View ◽  
Resonant Raman ◽  
Broad Feature

Resonant Raman spectroscopy has been employed to explore the first- and higher-order phonon spectra of several kinds of II-VI nanocrystals (NCs), with the aim of better understanding of the nature of phonon modes and forming a unified view onto the vibrational spectrum of semiconductor NCs. Particularly, besides the previously discussed TO, SO, LO, and 2LO modes, the combinational modes of TO+LO and SO+LO can be assumed to account for the lineshape of the spectrum below 2LO band. No trace of 2TO or 2SO band was detected, what can be the result of the dominance of Fröhlich mechanism in electron-phonon coupling in II-VI compounds. The resonant phonon Raman spectrum of NCs smaller than 2 nm is shown to be dominated by a broad feature similar to the SO mode of larger NCs or phonon density of states of a bulk crystal.

scholarly journals Evidence for superconductivity in Li-decorated monolayer graphene

2015 ◽  
Vol 112 (38) ◽  
pp. 11795-11799 ◽  
Author(s):  
B. M. Ludbrook ◽  
G. Levy ◽  
P. Nigge ◽  
M. Zonno ◽  
M. Schneider ◽  
...  
Keyword(s):  
Low Temperature ◽  
Photoemission Spectroscopy ◽  
Monolayer Graphene ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Phonon Coupling ◽  
Temperature Dependent ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Electron Phonon Coupling ◽  
First Time

Monolayer graphene exhibits many spectacular electronic properties, with superconductivity being arguably the most notable exception. It was theoretically proposed that superconductivity might be induced by enhancing the electron–phonon coupling through the decoration of graphene with an alkali adatom superlattice [Profeta G, Calandra M, Mauri F (2012) Nat Phys 8(2):131–134]. Although experiments have shown an adatom-induced enhancement of the electron–phonon coupling, superconductivity has never been observed. Using angle-resolved photoemission spectroscopy (ARPES), we show that lithium deposited on graphene at low temperature strongly modifies the phonon density of states, leading to an enhancement of the electron–phonon coupling of up to λ≃0.58. On part of the graphene-derived π∗-band Fermi surface, we then observe the opening of a Δ≃0.9-meV temperature-dependent pairing gap. This result suggests for the first time, to our knowledge, that Li-decorated monolayer graphene is indeed superconducting, with Tc≃5.9 K.

The solids phonon density of states reconstruction from the heat-type experiments: the computation resources

1998 ◽  
Vol 3 (0) ◽  
pp. 135-138
Author(s):  
В. М. Різак ◽  
І. М. Різак ◽  
І. П. Коссей ◽  
В. В. Маслюк
Keyword(s):  
Density Of States ◽  
Phonon Density ◽  
Phonon Density Of States

scholarly journals Phonon density of states in Fe/Cr(001) superlattices and Tb–Fe thin-film alloys

1999 ◽  
Vol 198-199 ◽  
pp. 590-592 ◽  
Author(s):  
W. Sturhahn ◽  
R. Roehlsberger ◽  
E.E. Alp ◽  
T. Ruckert ◽  
H. Schrör ◽  
...  
Keyword(s):  
Thin Film ◽  
Density Of States ◽  
Phonon Density ◽  
Phonon Density Of States

Excess Low Temperature Specific Heat and Related Phonon Density of States in a Modulated Incommensurate Dielectric

1996 ◽  
Vol 76 (13) ◽  
pp. 2334-2337 ◽  
Author(s):  
J. Etrillard ◽  
J. C. Lasjaunias ◽  
K. Biljakovic ◽  
B. Toudic ◽  
G. Coddens
Keyword(s):  
Low Temperature ◽  
Specific Heat ◽  
Density Of States ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Low Temperature Specific Heat
Sign in / Sign up

Export Citation Format

Share Document