Strong electron-lattice coupling as the mechanism behind charge density wave transformations in transition-metal dichalcogenides

Abstract

We consider single band of conduction electrons interacting with displacements of the transitional ions. In the classical regime strong enough coupling transforms the harmonic elastic energy for an ion to the one of the well with two deep minima, so that the system is described in terms of Ising spins. Inter-site interactions order spins at lower tempratures. Extention to the quantum regime is discussed. Below the CDW-transition the energy spectrum of electrons remains metallic because the structural vector Q and the FS sizes are not related. Large values of the CDW gap seen in the tunneling experiments correspond to the energy of the minima in the electron-ion two-well complex. The gap is defined through the density of states (DOS) inside the electronic bands below the CDW transition. We focus mainly on electronic properties of transition-metal dichalcogenides.

new references added; accepted for publication in Physical Review B. arXiv admin note: substantial text overlap with arXiv:1110.0432

References in corpus (4)

• Fermi surface nesting and the origin of Charge Density Waves in metals
• Two energy gaps and Fermi surface 'arcs' in NbSe2
• Quasi-Particle Spectra, Charge-Density-Wave, Superconductivity and Electron-Phonon Coupling in 2H-NbSe2
• Primary role of the barely occupied states in the charge density wave formation of NbSe2

Cited by in corpus (14)

• Strong enhancement of superconductivity at high pressures within the charge-density-wave states of 2H-TaS 2 and 2H-TaSe 2
• Strong anharmonicity induces quantum melting of charge density wave in 2H-NbSe$\_2$ under pressure
• Ultrafast dynamics of charge density waves in 4Hb-TaSe2 probed by femtosecond electron diffraction
• Order-disorder Peierls instability in the kagome metal (Cs,Rb)V${}_3$Sb${}_5$
• Coexistence of Superconductivity and Charge Density Wave in Tantalum Disulfide: Experiment and Theory
• Insight into the charge density wave gap from contrast inversion in topographic STM images
• Charge density waves and phonon-electron coupling in ZrTe${}_3$ investigated by Raman spectroscopy and first-principles calculations
• k-resolved susceptibility function of 2H-TaSe2 from angle-resolved photoemission
• Spectroscopic signature of the $\mathbf{k}$-dependent electron-phonon coupling in $2H$-TaS${}_2$
• Single crystal study of the charge density wave metal LuNiC2
• On the dual role of the d-electrons in iron-pnictides
• Condensation of collective charge ordering in Chromium
• Observation of anomalous amplitude modes in the kagome metal CsV${}_3$Sb${}_5$
• Instability of the charge density wave in Kagome magnet FeGe