Electron-Phonon Coupling in Superconducting Alkali-Metal Doped Fullerenes

1992 ◽  
Vol 270 ◽  
Author(s):  
R.A. Jishi ◽  
M.S. Dresseliiaus
Keyword(s):  
Experimental Data ◽  
Alkali Metal ◽  
Phonon Mode ◽  
Coupling Parameter ◽  
Tight Binding ◽  
Superconducting Transition ◽  
Phonon Coupling ◽  
Doped Fullerenes ◽  
Electron Phonon Coupling ◽  
Metal Doped

ABSTRACTThe dimensionless electron-phonon coupling parameter in alkali metal-doped fullerenes isevaluated in a model whereby the electrons are treated within a tight binding formalism.The phonon mode frequencies and eigenvectors are obtained from a lattice dynamical modelwhich accurately fits all available experimental data on these modes. It is shown that the electrormphonon interaction can account for the relatively high values of the superconducting transition temperatures in alkali-metal fullerenes.

scholarly journals MODIFIED TIGHT-BINDING APPROXIMATION AND ELECTRON-PHONON SPECTRAL FUNCTION FOR TRANSITION METALS

1990 ◽  
Vol 04 (07n08) ◽  
pp. 1395-1407 ◽  
Author(s):  
A.L. KUZEMSKY ◽  
A.P. ZHERNOV
Keyword(s):  
Transition Metals ◽  
Spectral Function ◽  
Strong Coupling ◽  
Coupling Parameter ◽  
Tight Binding ◽  
Numerical Calculations ◽  
Phonon Coupling ◽  
Tight Binding Approximation ◽  
Electron Phonon Coupling ◽  
Coupling Equations

The modified tight-binding approximation has been analyzed in detail and is applied to the derivation of an expression for electron-phonon spectral function (EPSF) which enters the strong coupling equations of superconductivity. Numerical calculations of the EPSF and the electron phonon coupling parameter λ for five transition metals, V, Nb, Mo, W, Ta have been performed.

scholarly journals Contribution of inter- and intraband transitions into electron–phonon coupling in metals

2021 ◽  
Vol 75 (7) ◽  
Author(s):  
Nikita Medvedev ◽  
Igor Milov
Keyword(s):  
Electron Scattering ◽  
Coupling Parameter ◽  
Exchange Process ◽  
Tight Binding ◽  
Phonon Coupling ◽  
Total Electron ◽  
Ion Energy ◽  
Interband Scattering ◽  
Electron Phonon Coupling ◽  
Dynamics Simulations

Abstract We recently developed an approach for calculation of the electron–phonon (electron–ion in a more general case) coupling in materials based on tight-binding molecular dynamics simulations. In the present work, we utilize this approach to study partial contributions of inter- and intraband electron scattering events into total electron–phonon coupling in Al, Au, and Cu elemental metals and in AlCu alloy. We demonstrate that the interband scattering plays an important role in the electron–ion energy exchange process in Al and AlCu, whereas intraband d–d transitions are dominant in Au and Cu. Moreover, inter- and intraband transitions exhibit qualitatively different dependencies on the electron temperature. Our findings should be taken into account for the interpretation of experimental results on the electron–phonon coupling parameter. Graphic abstract

Neutron Spectroscopy and Electron-Phonon Coupling in Alkali-Metal-Doped Fullerides

1992 ◽  
Vol 19 (7) ◽  
pp. 629-635 ◽  
Author(s):  
K Prassides ◽  
C Christides ◽  
M. J Rosseinsky ◽  
J Tomkinson ◽  
D. W Murphy ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Neutron Spectroscopy ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Metal Doped

TWO-COMPONENT SUPERCONDUCTIVITY FOR DOPED FULLERENES

1996 ◽  
Vol 10 (17) ◽  
pp. 823-829 ◽  
Author(s):  
JING LU ◽  
LIYUAN ZHANG
Keyword(s):  
Transition Temperature ◽  
Alkali Metal ◽  
Alkaline Earth ◽  
Component Model ◽  
Superconducting Transition ◽  
Specific Heat Jump ◽  
Doped Fullerenes ◽  
Two Component ◽  
Thermodynamic Critical Field ◽  
Metal Doped

The combining mechanism of the itinerant carrier pair and the local carrier pair (two-component model) is considered for doped fullerenes. The superconducting transition temperature T c , penetration depth λ, coherent length ξ, thermodynamic critical field H c and specific heat jump ΔC/T c are calculated and there is overall consistency between the calculations and the experiments for both alkali-metal-doped fullerenes ( Na 3 C 60, K 3 C 60, Rb 3 C 60 and RbCs 2 C 60) and alkaline-earth doped fullerenes ( Ba 6 C 60).

scholarly journals Electron-Phonon Coupling Parameter of Ferromagnetic Metal Fe and Co

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2755
Author(s):  
Kyuhwe Kang ◽  
Gyung-Min Choi
Keyword(s):  
Coupling Parameter ◽  
Critical Role ◽  
Circuit Modeling ◽  
Metallic Materials ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Complicated Process ◽  
G Value ◽  
Non Equilibrium

The electron-phonon coupling (g) parameter plays a critical role in the ultrafast transport of heat, charge, and spin in metallic materials. However, the exact determination of the g parameter is challenging because of the complicated process during the non-equilibrium state. In this study, we investigate the g parameters of ferromagnetic 3d transition metal (FM) layers, Fe and Co, using time-domain thermoreflectance. We measure a transient increase in temperature of Au in an FM/Au bilayer; the Au layer efficiently detects the strong heat flow during the non-equilibrium between electrons and phonons in FM. The g parameter of the FM is determined by analyzing the temperature dynamics using thermal circuit modeling. The determined g values are 8.8–9.4 × 1017 W m−3 K−1 for Fe and 9.6–12.2 × 1017 W m−3 K−1 for Co. Our results demonstrate that all 3d transition FMs have a similar g value, in the order of 1018 W m−3 K−1.

PATH-INTEGRAL APPROACH FOR ELECTRON–PHONON INTERACTION EFFECTS IN HARMONIC QUANTUM DOTS

1996 ◽  
Vol 10 (22) ◽  
pp. 2781-2796 ◽  
Author(s):  
SOMA MUKHOPADHYAY ◽  
ASHOK CHATTERJEE
Keyword(s):  
Quantum Dots ◽  
Path Integral ◽  
State Energy ◽  
Coupling Parameter ◽  
Three Dimensions ◽  
Integral Approach ◽  
Phonon Coupling ◽  
Electron Phonon Interaction ◽  
Electron Phonon Coupling ◽  
Parabolic Confinement

We use the Feynman–Haken path-integral formalism to obtain the polaronic correction to the ground state energy of an electron in a polar semiconductor quantum dot with parabolic confinement in both two and three dimensions. We perform calculations for the entire range of the electron–phonon coupling parameter and for arbitrary confinement length. We apply our results to several semiconductor quantum dots and show that the polaronic effect in some of these dots can be considerably large if the dot sizes are made smaller than a few nanometers.

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