CLOSELY SEPARATED ONE-DIMENSIONAL WIRES - COUPLED BALLISTIC CONDUCTION, WAVE-FUNCTION HYBRIDIZATION AND COMPRESSIBILITY INVESTIGATIONS

We report the experimental study of a system comprising two parallel q uasi-one-dimensional (1D) ballistic wires formed in a GaAs-AlxGa1-xAs double quantum well structure. A unique surface gate geometry allows t he device to be tuned smoothly from a configuration comprising a pair of vertically aligned 1D ballistic wires, to a single 1D ballistic wir e in either the upper or lower 2DES. We investigate coupled ballistic conduction in two samples with contrasting wire separations (35 and 30 0 Angstrom). The strongly coupled sample exhibits a cross-over from do uble to single wire conduction as the number of occupied 1D subbands i s reduced. The weakly coupled sample is used to observe directly varia tions in the compressibility of a single ballistic channel arising fro m the discrete 1D density of states. (C) 1998 Elsevier Science B.V. Al l rights reserved.