Electron-phonon coupling strength and implications for superconductivity in alkali-metal-doped fullerenes

1992 ◽  
Vol 45 (5) ◽  
pp. 2597-2600 ◽  
Author(s):  
R. A. Jishi ◽  
M. S. Dresselhaus
Keyword(s):  
Alkali Metal ◽  
Coupling Strength ◽  
Phonon Coupling ◽  
Doped Fullerenes ◽  
Electron Phonon Coupling ◽  
Metal Doped

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.

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

TRANSITION FREQUENCY OF STRONG-COUPLING IMPURITY BOUND POLARON IN AN ASYMMETRIC QUANTUM DOT

2012 ◽  
Vol 11 (03) ◽  
pp. 1250026 ◽  
Author(s):  
CHENG-SHUN WANG ◽  
YU-FANG CHEN ◽  
JING-JIN XIAO
Keyword(s):  
Excited State ◽  
Coupling Strength ◽  
State Energy ◽  
Transition Frequency ◽  
Phonon Coupling ◽  
Excited State Energy ◽  
Bound Polaron ◽  
Asymmetric Quantum Dot ◽  
Asymmetric Quantum ◽  
Electron Phonon Coupling

Properties of the excited state of strong-coupling impurity bound polaron in an asymmetric quantum dot are studied by using linear combination operator and unitary transformation methods. The first internal excited state energy, the excitation energy and the transition frequency between the first internal excited and the ground states of the impurity bound polaron as functions of the transverse and the longitudinal effective confinement lengths of the dot, the electron–phonon coupling strength and the Coulomb bound potential were derived. Our numerical results show that they will increase with decreasing the effective confinement lengths, due to interesting quantum size confining effects. But they are an increasing functions of the Coulomb bound potential. The first internal excited state energy is a decreasing function of the electron–phonon coupling strength whereas the transition frequency and the excitation energy are an increasing one of the electron–phonon coupling strength.

VIBRATIONAL FREQUENCY OF IMPURITY BOUND MAGNETOPOLARON IN AN ANISOTROPIC QUANTUM DOT

2009 ◽  
Vol 23 (20n21) ◽  
pp. 2449-2456 ◽  
Author(s):  
WEI XIAO ◽  
JING-LIN XIAO
Keyword(s):  
Quantum Dot ◽  
Interaction Energy ◽  
Coupling Strength ◽  
Vibrational Frequency ◽  
Cyclotron Frequency ◽  
Operator Method ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Anisotropic Quantum Dot ◽  
Bound Magnetopolaron

We study the vibrational frequency and the interaction energy of the weak-coupling impurity bound magnetopolaron in an anisotropic quantum dot. The effects of the transverse and longitudinal effective confinement lengths, the electron–phonon coupling strength, the cyclotron frequency of a magnetic field and the Coulomb bound potential are taken into consideration by using an improved linear combination operator method. It is found that the vibrational frequency and the interaction energy will increase rapidly with decreasing confinement lengths and increasing the cyclotron frequency. The vibrational frequency is an increasing function of the Coulomb bound potential, whereas the interaction energy is an decreasing one of the potential and the electron–phonon coupling strength.

INFLUENCE OF ELECTRON–PHONON INTERACTION ON EFFECTIVE MASS IN SOME HEAVY FERMION (HF) SYSTEMS

2008 ◽  
Vol 22 (04) ◽  
pp. 365-379 ◽  
Author(s):  
S. MOHANTY ◽  
B. K. KALTA ◽  
P. NAYAK
Keyword(s):  
Effective Mass ◽  
Coupling Strength ◽  
Heavy Fermion ◽  
Simple Expression ◽  
Model Parameters ◽  
Coupling Mechanism ◽  
Phonon Coupling ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Electron Phonon Coupling

It is a fact that for ordinary metals, the electron–phonon interaction increases the quasi-particle mass, which is in contrast to the finding by Fulde et al. that, for some heavy Fermion (HF) systems, it decreases. Some experiments on HF systems suggest that there exists a strong coupling of the elastic degrees of freedom with these at the electronic and magnetic ones. To understand the effect of electron–phonon interaction on effective mass, the electron–phonon coupling mechanism in the framework of the periodic Anderson model is considered, and a simple expression is derived. This involves various model parameters namely, the position of the 4f level; the effective coupling strength, g, temperature, b; and the electron–phonon coupling strength, r. The influence of these parameters on the value of effective mass is studied, and interesting results were found. For simplicity, the numerical calculation is performed in the long wavelength limit.

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