Local Interlayer Tunneling Between Two-Dimensional Electron Systems in the Ballistic Regime

We study a theoretical model of virtual scanning tunneling microscopy (VSTM), a proposed application of interlayer tunneling in a bilayer system to locally probe a two-dimensional electron system (2DES) in a semiconductor heterostructure. We consider tunneling for the case where transport in the 2DESs is ballistic, and show that the zero-bias anomaly is suppressed by extremely efficient screening. Since such an anomaly would complicate the interpretation of data from a VSTM, this result is encouraging for efforts to implement such a microscopy technique.