Electron-phonon interaction in charge-density-wave superconductors

1985 ◽  
Vol 31 (5) ◽  
pp. 2773-2775 ◽  
Author(s):  
S. N. Behera ◽  
S. G. Mishra
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Phonon Interaction ◽  
Electron Phonon Interaction

Charge density fluctuations and the softening of phonons in electron–phonon systems

1976 ◽  
Vol 54 (10) ◽  
pp. 1006-1010 ◽  
Author(s):  
Yasunari Kurihara
Keyword(s):  
Charge Density ◽  
Density Wave ◽  
Density Fluctuations ◽  
Electron Interaction ◽  
Periodic Lattice ◽  
Phonon Interaction ◽  
Phonon Softening ◽  
Wave State ◽  
Electron Phonon Interaction ◽  
Diagrammatic Method

The theory of charge–density fluctuations and phonon-softening is formulated exactly using the diagrammatic method for simple electron–phonon systems without many band effects and Umklapp processes. These electron–phonon systems are classified to three cases according to the strength of the electron–electron interaction and the electron–phonon interaction. The criteria for occurrence of the charge-density wave state and periodic lattice distortion are discussed in each case. They are given using the partial summation of diagrams. Here the phase transition is assumed to be of second order.

Charge Density Wave and Electron-Phonon Interaction in Epitaxial Monolayer NbSe2 Films

2021 ◽  
Vol 38 (10) ◽  
pp. 107101
Author(s):  
Xuedong Xie ◽  
Dongjing Lin ◽  
Li Zhu ◽  
Qiyuan Li ◽  
Junyu Zong ◽  
...  
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Liquid Nitrogen Temperature ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Electron Phonon Interaction ◽  
Electron Phonon Coupling ◽  
Device Applications

Understanding the interplay between superconductivity and charge-density wave (CDW) in NbSe2 is vital for both fundamental physics and future device applications. Here, combining scanning tunneling microscopy, angle-resolved photoemission spectroscopy and Raman spectroscopy, we study the CDW phase in the monolayer NbSe2 films grown on various substrates of bilayer graphene (BLG), SrTiO3(111), and Al2O3(0001). It is found that the two stable CDW states of monolayer NbSe2 can coexist on NbSe2/BLG surface at liquid-nitrogen temperature. For the NbSe2/SrTiO3(111) sample, the unidirectional CDW regions own the kinks at ±41 meV and a wider gap at 4.2 K. It is revealed that the charge transfer from the substrates to the grown films will influence the configurations of the Fermi surface, and induce a 130 meV lift-up of the Fermi level with a shrink of the Fermi pockets in NbSe2/SrTiO3(111) compared with the NbSe2/BLG. Combining the temperature-dependent Raman experiments, we suggest that the electron-phonon coupling in monolayer NbSe2 dominates its CDW phase transition.

Incommensurate modulated phases of the NbxTa1-xTe4 charge density wave system

1992 ◽  
Vol 50 (1) ◽  
pp. 58-59
Author(s):  
S. Ritchie ◽  
J. C. Bennett ◽  
A. Prodan ◽  
F.W. Boswell ◽  
J.M. Corbett
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Direct Evidence ◽  
Density Wave ◽  
Wave System ◽  
Modulated Phases ◽  
Metal Atoms ◽  
Incommensurate Modulation ◽  
End Members ◽  
Modulation Wave Vector

A continuous sequence of compounds having composition NbxTa1-xTe4; 0 ≤ x ≤ 1 have been studied by electron diffraction and microscopy. Previous studies have shown that the end members of the series, TaTε4 and NbTε4 possess a quasi-one-dimensional character and exhibit charge density wave (CDW) distortions. In these compounds, the subcell structure is tetragonal with axes (a × a × c) and consists of the metal atoms (Nb or Ta) centered within an extended antiprismatic cage of Te atoms. At room temperature, TaTε4 has a commensurate modulation structure with a 2a × 2a × 3c unit cell. In NbTε4, an incommensurate modulation with × ∼ 16c axes is observed. Preliminary studies of the mixed compounds NbxTα1-xTε4 showed a discontinuous jump of the modulation wave vector commensurate to incommensurate when the Nb dopant concentration x, exceeded x ≃ 0.3, In this paper, the nature of the compositional dependence of is studied in greater detail and evidence is presented for a stepwise variation of . This constitutes the first direct evidence for a Devil's staircase in CDW materials.

Wave Analysis of the Charge Density Wave Dynamics in the Molecular Conductor (Perylene)2Pt(mnt)2 (mnt=maleonitriledithiolate)

1995 ◽  
Vol 5 (5) ◽  
pp. 539-545 ◽  
Author(s):  
J. Dumas ◽  
N. Thirion ◽  
M. Almeida ◽  
E. B. Lopes ◽  
M. J. Matos ◽  
...  
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Wave Analysis ◽  
Wave Dynamics ◽  
Molecular Conductor
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