arXiv subjects

G. Finkelstein

Publications and source records attributed to G. Finkelstein.

21 records · Page 2Linked to original sources

arXiv2001

Direct observation of the charging of a 2D electron gas through an incompressible strip in the quantum Hall regime

Using charge accumulation imaging, we measure the charge flow across an incompressible strip and follow its evolution with magnetic field. The strip runs parallel to the edge of a gate deposited on the sample and forms at positions where an exact number of integer Landau levels is filled. An RC model of charging fits the data well and enables us to determine the longitudinal resistance of the strip. Surprisingly, we find that the strip becomes more resistive as its width decreases.

cond-mat.mes-hall↗

arXiv2000

Topographic Mapping of the Quantum Hall Liquid using a Few-Electron Bubble

A scanning probe technique was used to obtain a high-resolution map of the random electrostatic potential inside the quantum Hall liquid. A sharp metal tip, scanned above a semiconductor surface, sensed charges in an embedded two-dimensional electron gas. Under quantum Hall effect conditions, applying a positive voltage to the tip locally enhanced the 2D electron density and created a ``bubble'' of electrons in an otherwise unoccupied Landau level. As the tip scanned along the sample surface, the bubble followed underneath. The tip sensed the motions of single electrons entering or leaving the bubble in response to changes in the local 2D electrostatic potential.

cond-mat.mes-hall↗

arXiv1999

Imaging of Low Compressibility Strips in the Quantum Hall Liquid

Using Subsurface Charge Accumulation scanning microscopy we image strips of low compressibility corresponding to several integer Quantum Hall filling factors. We study in detail the strips at Landau level filling factors $ν=$ 2 and 4. The observed strips appear significantly wider than predicted by theory. We present a model accounting for the discrepancy by considering a disorder-induced nonzero density of states in the cyclotron gap.

cond-mat.mes-hall↗