We study the static and dynamic properties of the Fukuyama-Lee-Rice model for charge-density waves pinned by random impurities by means of a self-consistent Gaussian approximation. A depinning transition is observed, from an insulating to a conductive phase, when the external field E is raised above a critical value Ec, which depends both on the elastic coupling constant and on the disorder strength. The dynamics are characterized by an early stage followed by a crossover to an asymptotic regime. In the depinned phase a stationary periodic state is attained for long times characterized by a scaling behavior of the average current J̄, namely, J̄∼(E-Ec)ω, with ω=0.497±0.004.
Gaussian solution of a charge-density-wave model
CORBERI, Federico
1997
Abstract
We study the static and dynamic properties of the Fukuyama-Lee-Rice model for charge-density waves pinned by random impurities by means of a self-consistent Gaussian approximation. A depinning transition is observed, from an insulating to a conductive phase, when the external field E is raised above a critical value Ec, which depends both on the elastic coupling constant and on the disorder strength. The dynamics are characterized by an early stage followed by a crossover to an asymptotic regime. In the depinned phase a stationary periodic state is attained for long times characterized by a scaling behavior of the average current J̄, namely, J̄∼(E-Ec)ω, with ω=0.497±0.004.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
