CHARGE DENSITY WAVE TRANSITIONS IN TWO-DIMENSIONAL TRANSITION METAL BRONZES AND OXIDES

1993 ◽  
Vol 07 (23n24) ◽  
pp. 3973-4003 ◽  
Author(s):  
P. FOURY ◽  
J.P. POUGET
Keyword(s):  
Transition Metal ◽  
Charge Density ◽  
Ground State ◽  
Charge Density Wave ◽  
Density Wave ◽  
Electron Localization ◽  
Two Dimensional ◽  
Fermi Surfaces ◽  
A Charge ◽  
Structural Instabilities

The structural instabilities towards the formation of a charge density wave (CDW) ground state exhibited by several layered Mo and W bronzes and oxides are reviewed. It is shown that in these two-dimensional (2D) metals, including the purple bronzes A x Mo 6 O 17 (A=K, Na, Tl; x≈1), the γ and η phases of MO 4 O 11 and the monophosphate tungsten bronzes with pentagonal tunnels ( PO 2)4 ( WO 3)2m(m=4, 6, 7), the CDW instability can be associated with particular chains of MoO 6 or WO 6 octahedra of the ReO 3 type slabs along which there is a strong overlap of the t 2g orbitals. The CDW critical wave vectors of the purple bronzes, Mo 4 O 11 and the tungsten bronzes with m=4 and 6 lead to a common nesting between differently oriented 1D Fermi surfaces. It is suggested that the anharmonic CDW modulation, which occurs in the tungsten bronzes with m≥7, could be the structural fingerprint of electron localization effects.

scholarly journals Suppression of a charge-density-wave ground state in high magnetic fields: Spin and orbital mechanisms

2004 ◽  
Vol 69 (12) ◽  
Author(s):  
D. Graf ◽  
J. S. Brooks ◽  
E. S. Choi ◽  
S. Uji ◽  
J. C. Dias ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Charge Density ◽  
Ground State ◽  
Charge Density Wave ◽  
Density Wave ◽  
High Magnetic Fields ◽  
A Charge

Features of Pinning of a Charge-Density Wave in Quasi-Two-Dimensional Compounds

JETP Letters ◽  
2019 ◽  
Vol 109 (3) ◽  
pp. 203-206 ◽  
Author(s):  
A. V. Frolov ◽  
A. P. Orlov ◽  
A. A. Sinchenko ◽  
P. Monceau
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Two Dimensional ◽  
A Charge

Pseudogapped Fermi surfaces of1T−TaS2and1T−TaSe2:A charge density wave effect

2004 ◽  
Vol 69 (12) ◽  
Author(s):  
M. Bovet ◽  
D. Popović ◽  
F. Clerc ◽  
C. Koitzsch ◽  
U. Probst ◽  
...  
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Wave Effect ◽  
Fermi Surfaces ◽  
A Charge

The Effects of Transition Metal Substitutions in the NbTe4-TaTe4 Charge-Density Wave System

1992 ◽  
Vol 45 (9) ◽  
pp. 1363 ◽  
Author(s):  
JC Bennett ◽  
FW Boswell ◽  
A Prodan ◽  
JM Corbett ◽  
S Ritchie
Keyword(s):  
Transition Metal ◽  
Charge Density ◽  
Charge Density Wave ◽  
Room Temperature ◽  
Density Wave ◽  
Dark Field ◽  
Wave System ◽  
Incommensurate Modulation ◽  
High Concentrations ◽  
A Charge

At room temperature, the structures of TaTe4 and NbTe4 are modulated by the presence of a charge-density wave which in the former compound is commensurate with the parent lattice and in the latter incommensurate. In addition, a series of incommensurate mixed crystals ( Tal-xNbx )Te4 (0 ≤ x ≤) exist in which the modulation wavevector increases as a function of x. In this paper, we report the occurrence of a systematic variation in the period of the charge-density wave upon substitution of the transition metal elements Ti, Zr or V for either Nb or Ta. Electron diffraction experiments reveal that, in TaTe4, substitutions of Group 4 elements Ti and Zr result in an incommensurate modulation with a decrease in the modulation wavevector q. In NbTe4, substitutions of Ti or Zr also reduce q, in this case towards the commensurate value, and, at sufficiently high concentrations, a commensurate phase is stabilized at room temperature. Vanadium substitutions in NbTe4 result in a slight increase in q. Satellite dark-field images reveal the presence of defects in the modulation structures of the doped crystals. The above results are discussed in terms of the factors which determine the charge-density wave periodicity in the NbTe4-TaTe4 system.

Non-equilibrium charge density wave ground state of quasi-two-dimensional rare-earth tritelluride TbTe3

2021 ◽  
Vol 118 (25) ◽  
pp. 253102
Author(s):  
A. V. Frolov ◽  
A. P. Orlov ◽  
D. M. Voropaev ◽  
A. Hadj-Azzem ◽  
A. A. Sinchenko ◽  
...  
Keyword(s):  
Rare Earth ◽  
Charge Density ◽  
Ground State ◽  
Charge Density Wave ◽  
Density Wave ◽  
Two Dimensional ◽  
Equilibrium Charge ◽  
Non Equilibrium

scholarly journals Quasi-one-dimensional superconductivity in the pressurized charge-density-wave conductor HfTe3

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Z. Y. Liu ◽  
J. Li ◽  
J. F. Zhang ◽  
J. Li ◽  
P. T. Yang ◽  
...  
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Ambient Pressure ◽  
Density Wave ◽  
Fermi Surfaces ◽  
One Dimensional ◽  
Transmission Electron ◽  
Pressure Transport ◽  
A Charge ◽  
Superconducting Pairing

AbstractHfTe3 single crystal undergoes a charge-density-wave (CDW) transition at TCDW = 93 K without the appearance of superconductivity (SC) down to 50 mK at ambient pressure. Here, we determined its CDW vector q = 0.91(1) a* + 0.27(1) c* via low-temperature transmission electron microscope and then performed comprehensive high-pressure transport measurements along three major crystallographic axes. Our results indicate that the superconducting pairing starts to occur within the quasi-one-dimensional (Q1D) -Te2-Te3- chain at 4–5 K but the phase coherence between the superconducting chains cannot be realized along either the b- or c-axis down to at least 1.4 K, giving rise to an extremely anisotropic SC rarely seen in real materials. We have discussed the prominent Q1D SC in pressurized HfTe3 in terms of the anisotropic Fermi surfaces arising from the unidirectional Te-5px electronic states and the local pairs formed along the -Te2-Te3- chains based on the first-principles electronic structure calculations.

scholarly journals Holographic Fermi surfaces in charge density wave from D2-D8

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Subir Mukhopadhyay ◽  
Nishal Rai
Keyword(s):  
Dirac Equation ◽  
Fermi Surface ◽  
Spectral Density ◽  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Spin Density Wave ◽  
Fermi Surfaces ◽  
A Charge ◽  
Ionic Lattice

Abstract D2-D8 model admits a numerical solution that corresponds to a charge density wave and a spin density wave. Considering that as the background, we numerically solve the Dirac equation for probe fermions. From the solution, we obtain the Green’s function and study the behaviour of the spectral density. We begin with generic fermions and have studied the formation of the Fermi surface and where it develops a gap. In addition, we have incorporated an ionic lattice and study its effect on the Fermi surface. Then we analysed the worldvolume fermions. In this particular model we do not find Fermi surface for the dual operators.

scholarly journals Novel Mechanism of a Charge Density Wave in a Transition Metal Dichalcogenide

2007 ◽  
Vol 99 (21) ◽  
Author(s):  
D. W. Shen ◽  
B. P. Xie ◽  
J. F. Zhao ◽  
L. X. Yang ◽  
L. Fang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Transition Metal Dichalcogenide ◽  
A Charge
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