LINEAR-RESPONSE THEORY OF INTER-QUANTUM-WELL TUNNELING IN A DOUBLE-WELL STRUCTURE WITH INPLANE MAGNETIC-FIELDS

A linear response theory of incoherent tunnelling is presented and compared to data for the 2D-2D inter-quantum-well conductance for a double-well structure with an external in-plane magnetic field. The tunnelling conductance, calculated by evaluating the current-current correlation function, shows resonances as a function of the magnetic field. The widths and heights of the resonance peaks depend sensitively on the intra-well scattering times and temperature. Tunnelling occurs not only through the ground-energy sublevels but also through the higher-energy sublevels which can be important at high temperatures. Using a differential transmission-line model, analytic relationships between the source-drain conductance and the tunnelling conductance are derived. The theoretical results yield reasonable agreement with the tunnelling conductance data obtained from this relationship.