BISTABILITY AND DYNAMIC DEPOPULATION IN TRANSPORT THROUGH A SYSTEM OFWEAKLY COUPLED QUANTUM WIRES

We study conductance through a system of weakly coupled narrow wires f ormed in the plane of a GaAs/AlxGa1-xAs heterojunction, where a voltag e V-ds is applied perpendicular to the wires, in the plane. We find an abrupt onset of current as V-ds is increased beyond a certain critica l value. In contrast, when V-ds is swept down there is a gradual decre ase in current which extends well below the critical V-ds. The abrupt onset and the hysteresis are interpreted in terms of a bistability of the system, where the conducting state is associated with dynamic depo pulation of the wires. Additional features in the conductance are also observed and discussed.