Scanning gate microscopy
Scanning gate microscopy (SGM) is a scanning probe microscopy technique with an electrically conductive tip used as a movable gate that couples capacitively to the sample and probes electrical transport on the nanometer scale.[1][2] Typical samples are mesoscopic devices, often based on semiconductor heterostructures, such as quantum point contacts or quantum dots. Carbon nanotubes too have been investigated.
Operating principle
[edit]In SGM one measures the sample's electrical conductance as a function of tip position and tip potential. This is in contrast to other microscopy techniques where the tip is used as a sensor, e.g., for forces.
Development
[edit]SGMs were developed in the late 1990s from atomic force microscopes. Most importantly, these had to be adapted for use at low temperatures, often 4 kelvins or less, as the samples under study do not work at higher temperatures. Today an estimated number of eleven research groups worldwide use the technique.
References
[edit]- ^ Sellier, H; Hackens, B; Pala, M G; Martins, F; Baltazar, S; Wallart, X; Desplanque, L; Bayot, V; Huant, S (2011). "On the imaging of electron transport in semiconductor quantum structures by scanning-gate microscopy: successes and limitations". Semiconductor Science and Technology. 26 (6): 064008. arXiv:1104.2032. Bibcode:2011SeScT..26f4008S. doi:10.1088/0268-1242/26/6/064008. ISSN 0268-1242.
- ^ Gorini, Cosimo; Jalabert, Rodolfo A.; Szewc, Wojciech; Tomsovic, Steven; Weinmann, Dietmar (2013). "Theory of scanning gate microscopy". Physical Review B. 88 (3). arXiv:1302.1151. Bibcode:2013PhRvB..88c5406G. doi:10.1103/PhysRevB.88.035406. ISSN 1098-0121.
