A model of coherent creep and switching in charge density wave conduction in NbSe3 at low temperatures

2002 ◽  
Vol 12 (9) ◽  
pp. 161-164
Author(s):  
J. C. Gill
Keyword(s):  
Charge Density ◽  
Dislocation Loop ◽  
Low Temperatures ◽  
Charge Density Wave ◽  
Density Wave ◽  
Threshold Field ◽  
Niobium Triselenide ◽  
Conducting State ◽  
Thermally Activated

A model is proposed of the temporally ordered collective creep with finite threshold field, and of the “switching" transition to a hgNy conducting state at a higher threshold, observed in charge-density wave conduction in niobium triselenide by Lemay et al. [phys. Rev. Lett. 83,2793 (1999)]. The model is based on their suggestion that the creep involves the thermally activated advance of wavelengths of CDW past individual impurities. In the model this is achieved by the formation near the impurity of a dislocation loop, which collapses after encircling it. Switching is attributed to a transition, induced by stress associated with the motion, to a situation in which collapse is avoided, enabling the CDW to advance indefinitely. The model accounts quantitatively for the observed creep, and exhibits switching and hysteresis qualitatively similar to that observed.

Mechanically-induced Shapiro steps: the effect of vibration on the dynamics of a charge density wave

2021 ◽  
Author(s):  
M.V. Nikitin ◽  
S.G. Zybtsev ◽  
V.Ya. Pokrovskii ◽  
B.A. Loginov
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Electromechanical Coupling ◽  
Density Wave ◽  
Threshold Field ◽  
Microwave Range ◽  
One Dimensional ◽  
Shapiro Steps ◽  
Orthorhombic Modification ◽  
A Charge

Problem formulating. The quasi one-dimensional conductor TaS3 of the orthorhombic modification shows strong electromechanical coupling of the sliding charge density wave (CDW) with the lattice of crystals. However, until now the effect of the dynamic deformation of the sample on the CDW sliding has not been studied. Goal. Search and study of a new effect: the influence of sample vibration on CDW dynamics. Result. The conductivity of TaS3 samples is studied as a function of the electric field and the frequency of mechanical deformation of the sample. It is found that when the vibration frequency of the piezoelectric actuators deforming the sample coincides with one of the mechanical resonances of the sample, suppression of the threshold field and features in the form of Shapiro steps are observed on the I–V characteristics. The effect is similar (though not equivalent) to that of RF voltage applied directly to the sample at the same frequency. Evidence is provided that these features are not coupled with the effect of electrical interference. Practical meaning. The result opens up a new area of electromechanical effects in quasi one-dimensional conductors with CDW and can be used for detecting and processing of mechanical oscillations in the microwave range.

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