Mesoscopic effects in tunneling between parallel quantum wires - art. no. 085315

We consider a phase-coherent system of two parallel quantum wires that are coupled via a tunneling barrier of finite length. The usual perturbative tr eatment of tunneling fails in this case, even in the diffusive limit, once the length L of the coupling region exceeds a characteristic length scale L , set by tunneling. Exact solution of the scattering problem posed by the e xtended tunneling barrier allows us to compute tunneling conductances as a function of applied voltage and magnetic field. We take into account chargi ng effects in the quantum wires due to applied voltages and find that these are important for one-dimensional-to-one-dimensional tunneling transport.