Josephson effect in spin- or charge-gapped one-dimensional systems

We calculate Josephson current through one-dimensional systems with a spin gap, i.e. Luther-Emery solution, or a charge gap, applying the bosonization method. For the spin-gapped liquid, the gap formation is irrelevant for th e Josephson current. On the other hand, formation of the charge gap suppres ses the magnitude of the maximum Josephson current at low temperatures. (C) 2000 Elsevier Science Ltd. All rights reserved.