Effect of impurity pinning on conduction and specific heat in the Luttinger liquid

We study theoretically two effects related to impurity depinning that are common for 1D Luttinger liquid (LL) and linear-chain charge-density wave (CDW) conductors. First, we consider the electron transport through a single impurity in a 1D conducting channel and study a new regime of conduction related to LL sliding at voltage above a threshold one. The DC current in this regime is accompanied by oscillations with frequency f=I/ef=I/e. This resembles the CDW depinning in linear-chain conductors, the Josephson effect, and the Coulomb blockade. Second, we found that strong pinning of the LL by impurities leads to a magnetic field dependence of the low-temperature specific heat similar to that observed experimentally in CDW compounds. We interpret this in favor of possibility of formation of the LL in linear-chain compounds.