Space-time distributions of solitons for the current conversion problem in charge density waves
Abstract
Dissipative dynamics equations of Charge Density Waves (CDW) are derived for a homogeneous distribution of solitons and dislocations. Response functions for the CDW current and for the electric field are found for a spontaneous conversion process of electrons into solitons. A one- dimentional development of the injection current impulse is studied in details. The problem is investigated for a purely dissipative CDW regime and within a diffusion approximation for solitons. We find that first the nominal CDW current j_infty, which is due to the CDW phase velocity β_{infty}=-π j_{infty}, and the electric field E_{infty} propto j_{infty} are established along the sample length in a very short time. Later on the diffusion front passes along with a constant velocity bE_{infty}, where b is a mobility of solitons. It is followed by the growth of the soliton concentration ρ_s and by the decrease of local coherent CDW current j(x,t) propto β(x,t). At largest time t they are related as j(x,t) propto ρ_s^{-1} propto t^{-1/3}. The total electric current is nearly additive J≈ j+2j_s being almost constant. Also a stationary distribution is studied for generation of solitons at the presence of a constant CDW current. It is characterized by a step-like profile of the defects concentration.
- Publication:
-
Journal de Physique I
- Pub Date:
- May 1992
- DOI:
- 10.1051/jp1:1992176
- Bibcode:
- 1992JPhy1...2..725B