Virtual scanning tunneling microscopy: A local spectroscopic probe of two-dimensional electron systems

We propose a probe technique capable of performing local low-temperature spectroscopy on a two-dimensional electron system (2DES) in a semiconductor heterostructure. Motivated by predicted spatially-structured electron phases, the probe uses a charged metal tip to induce electrons to tunnel locally, directly below the tip, from a probe 2DES to a subject 2DES of interest. We test this concept with large-area (nonscanning) tunneling measurements, and predict a high spatial resolution and spectroscopic capability, with minimal influence on the physics in the subject 2DES. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3492440]