Impurities potential effect on the charge density wave dynamics in one-dimensional systems

Abstract

In this work, we present in the weak pinning case the numerical simulation results of the one-dimensional deformable charge density wave (CDW) properties considering the potential amplitude fluctuations effect generated by different impurity types randomly distributed in the lattice. When the electric field approaches threshold value E T , the static equilibrium characteristic time τ and the polarization P CDW become large and seem to diverge at critical field E cr from below E T following a power law [ 1 − ( E / E cr ) ] − α where α is an impurity dependant critical exponent. This divergence indicates that the CDW depinning can be described in terms of a dynamical critical phenomena, where the critical field E cr plays the role of a transition temperature as in ordinary phase transitions. In agreement with several experimental results, we show that the electric current density J CDW and electric conductivity σ CDW follow respectively a power law [ ( E / E T ) − 1 ] β and ( E T / E ) [ ( E / E T ) − 1 ] ν where β and ν are critical exponents. This results are analogous to these obtained in the case of one impurity type.