QUANTUM TRANSPORT AND PINNING OF A ONE-DIMENSIONAL WIGNER CRYSTAL

We study electron transport along a strongly depleted one-dimensional channel and assume the limit of very weak disorder when electrons form the Wigner crystal. Pinning of this crystal by a weak potential of single impurity is considered in the quantum case. Zero-point oscillations of the crystal significantly diminish the pinning barrier. However, it remains finite at moderate densities of electrons (na(B) less than or similar to 0.5), in spite of the absence of the long-range order in one dimension. Charge transfer in the system occurs due to thermally assisted tunneling of the crystal through the pinning barrier, which results in a power-law temperature dependence of the conductance sigma(T). The nonlinear conductance sigma(U) at T = 0 obeys a similar law.