2006/10/30 by A. Baumgärtner, Thomas Ihn, K. Ensslin +4 · 1 citation
Physics and Astronomy · Engineering · #Quantum and electron transport phenomena #Surface and Thin Film Phenomena #Advancements in Semiconductor Devices and Circuit Design
paper · doi:10.1103/physrevb.74.165426
openalex publication_date 2006/10/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Scanning gate experiments on a two-dimensional electron gas in the regime of the classical Hall effect are presented. The Hall resistance is recorded while tuning the local potential by applying a voltage to the metallic tip of a scanning force microscope. In diffusive samples and at zero magnetic field an intriguing Hall resistance pattern arises that is attributed to tip-induced inhomogeneous current flow. Measurements at small, i.e., nonquantizing, magnetic fields reveal an additional Hall resistance pattern due to the tip-induced inhomogeneous electron density in the Hall cross. Deviations of the measurements on higher-mobility samples from expectations based on symmetry arguments are used to distinguish the diffusive from the mesoscopic transport regime. Finite-element-method modeling for the diffusive regime and trajectory calculations for ballistic electrons allow a concise interpretation of the measurements.