SUBMICROMETER CONTROL OF 2-DIMENSIONAL 2-DIMENSIONAL MAGNETOTUNNELING IN DOUBLE-WELL HETEROSTRUCTURES

Interwell two-dimensional-two-dimensional (2D-2D) tunneling in a density-imbalanced double-well heterostructure is studied in an in-plane magnetic field using a gated-bridge technique which does not require independent contacts to the two 2D electron layers. Two sharp peaks in the tunneling conductance at B less-than-or-equal-to 1.3 T and B = 5-6 T are explained using a linear-response theory which incorporates finite scattering and is based on a field-induced momentum shift of the two quantum wells' Fermi circles. A second gate is used to locally enhance tunneling on a submicrometer length scale.