Dresden 2026 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 25: Focus Session: Young Semiconductor Forum
HL 25.4: Invited Talk
Wednesday, March 11, 2026, 11:15–11:45, POT/0251
Tunability of quantized Hall plateaus — •Serkan Sirt1, Vladimir Umansky2, and Stefan Ludwig1 — 1Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Berlin, Germany — 2Weizmann Institut of Science, Rehovot, Israel
The textbook single-particle description of the quantum Hall effect based on the Landauer-Büttiker picture explains the extent of quantized Hall plateaus as a function of magnetic field in terms of disorder-broadened Landau levels. In contrast, the screening theory includes electron-electron interactions and predicts the formation of extended Hall plateaus based on the confinement potential, without the need for disorder [1].
To test these contrasting models, we investigate the tunability of the plateaus in gate-defined Hall bars. We employ a global top gate to deplete the two-dimensional electron system and an additional screen gate on the sample surface, separated by an insulating layer, to define the Hall bar. Varying the gate voltages allows us to tune the edges of the Hall bar continuously from hard to soft confinement. We find that, for softer confinement, the plateaus become wider by extending to lower magnetic fields. These results support the screening theory and are inconsistent with the Landauer-Büttiker picture.
This work establishes a new method for controlling and manipulating quantized Hall plateaus, which may become relevant for quantum Hall metrology and quantum technology applications.
[1] R. R. Gerhardts, Phys. Status Solidi B 245, 378 (2008)
Keywords: quantum Hall effect; screening theory; extended Hall plateau; gate-defined Hall bar