Coulomb Blockade of the Collective Current in Charge-Density-Wave Systems

Abstract

The Coulomb-interaction effect on the phase slip in charge-density-wave (CDW) systems is studied theoretically. Sliding motion of the CDW is accompanied by thermally activated phase-slip processes near electrical contacts. We calculate the thermal nucleation rate of the phase slip taking account of the Coulomb-interaction effect on dislocation loops. We find that the effect manifests itself when the quasiparticle screening length λ qp is much longer than the longitudinal phason screening length λ ph . It is shown that due to a large charging energy associated with the dislocation-loop nucleation, the phase-slip rate is greatly reduced when the applied voltage is smaller than the threshold voltage \(V_{\text{th}} \sim \gamma \hbar v_{\text{F}}/(e \lambda_{\text{ph}})\) (γ: anisotropy constant, v F : Fermi velocity). This indicates that the collective CDW current below the threshold voltage is strongly suppressed by the Coulomb blockade of the phase slip.