A low-temperature scanning force microscope for investigating buried two-dimensional electron systems under quantum Hall conditions

• Published in: Applied surface science Vol. 157; no. 4; pp. 349 - 354
• Main Authors: Weitz, P, Ahlswede, E, Weis, J, Klitzing, K.v, Eberl, K
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2000; Elsevier Science
• Subjects: Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Kelvin probe force microscopy; Physics; Quantum Hall effect; Scanning probe microscopes, components and techniques; Scanning probe microscopy; Scanning probe microscopy; 73.40H; Kelvin probe force microscopy; 07.79; Quantum Hall effect; KE; HC; SB20; Two-dimensional systems; Submicrometer; Scanning force microscopy; Measuring methods; Kelvin probe; Experimental study; Spatial resolution; Surface potential; Low temperature
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(99)00550-4

A low-temperature scanning force microscope sensitive to electrostatics has been constructed for investigating a two-dimensional electron system (2DES) under quantum Hall conditions. In order to cope with the highly resistive properties of the 2DES under these conditions, a low-frequency measurement technique is presented, based on the shift of the cantilever's resonance frequency induced by a small ac current modulation within the 2DES. Since the 2DES is buried in a GaAs/AlGaAs heterostructure, a special calibration technique has to be applied, which allows to map Hall-potential profiles with clearly submicron resolution.