Abstract: A transistor comprising a first layer comprising a first material; a second layer comprising a second material applied directly onto the first layer, the first layer of the first material and the second layer of the second material forming a first heterojunction; a first 2-dimensional gas (2DEG) layer in the first layer adjacent the first heterojunction, a plane of the 2DEG layer being parallel to the first heterojunction; a source electrode and a drain electrode fixed on the second layer opposite the first layer; a nanogap between the source electrode and the drain electrode, the nanogap extending through the first layer and at least partially through the second layer beyond the plane of the 2DEG layer, the nanogap arranged perpendicular to the heterojunction; and one or more gates arranged adjacent the source electrode. The nanogap is between about 30-50 nm in width.