Scanning gate microscopy of quantum rings: effects of an external magnetic field and of charged defects
Pala, M G; Baltazar, S; Martins, F; Hackens, B; Sellier, H; Ouisse, T; Bayot, V; Huant, S; Pala, M G; IMEP-LAHC, Grenoble INP Minatec, BP 257, F-38016 Grenoble, France; Baltazar, S; IMEP-LAHC, Grenoble INP Minatec, BP 257, F-38016 Grenoble, France; Martins, F; CERMIN, DICE Lab, UCL, B-1348 Louvain-la-Neuve, Belgium; Hackens, B; CERMIN, DICE Lab, UCL, B-1348 Louvain-la-Neuve, Belgium; Sellier, H; Institut Néel, CNRS and Université Joseph Fourier, BP 166, F-38042 Grenoble, France; Ouisse, T; LMGP, Grenoble INP Minatec, F-38016 Grenoble, France; Bayot, V; CERMIN, DICE Lab, UCL, B-1348 Louvain-la-Neuve, Belgium ; Institut Néel, CNRS and Université Joseph Fourier, BP 166, F-38042 Grenoble, France; Huant, S; Institut Néel, CNRS and Université Joseph Fourier, BP 166, F-38042 Grenoble, France
Журнал:
Nanotechnology
Дата:
2009-07-01
Аннотация:
We study scanning gate microscopy (SGM) in open quantum rings obtained from buried semiconductor InGaAs/InAlAs heterostructures. By performing a theoretical analysis based on the Keldysh–Green function approach we interpret the radial fringes observed in experiments as the effect of randomly distributed charged defects. We associate SGM conductance images with the local density of states (LDOS) of the system. We show that such an association cannot be made with the current density distribution. By varying an external magnetic field we are able to reproduce recursive quasi-classical orbits in LDOS and conductance images, which bear the same periodicity as the Aharonov–Bohm effect.
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