SUBMICROMETER CONTROL OF 2-DIMENSIONAL 2-DIMENSIONAL MAGNETOTUNNELINGIN DOUBLE-WELL HETEROSTRUCTURES

Interwell two-dimensional-two-dimensional (2D-2D) tunneling in a densi ty-imbalanced double-well heterostructure is studied in an in-plane ma gnetic field using a gated-bridge technique which does not require ind ependent contacts to the two 2D electron layers. Two sharp peaks in th e 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 finit e scattering and is based on a field-induced momentum shift of the two quantum wells' Fermi circles. A second gate is used to locally enhanc e tunneling on a submicrometer length scale.