arXiv subjects

Serkan Sirt

Publications and source records attributed to Serkan Sirt.

3 recordsLinked to original sources

arXiv2026

Current density distribution for the quantum Hall effect

Our microscopic understanding of the integer quantum Hall effect is still incomplete. For decades, there has been a controversial discussion about "where the current flows" if the Hall resistance is quantized. Here, we qualitatively analyze the current density distribution in a Hall bar based on the screening properties of a two-dimensional electron system in the quantum Hall regime. Beyond previous publications, we include a closed loop persistent current that exists inside a Hall bar if the Hall resistance is quantized. We find, that the persistent current density decreases with increasing Hall voltage. Accounting for this dependence, we find, that the current flows in the opposite directions along opposite edges of the Hall bar, while the imposed current flows unidirectionally and only on the side of the Hall bar connected with its higher electrical potential edge.

cond-mat.mes-hall↗

arXiv2025

Nature of current flow in the regime of the quantum Hall effect

The integer quantum Hall effect (QHE) belongs to the most fundamental phenomena of solid state physics and has an important application as resistance standard. It serves as a basis to understand the fractional, anomalous or spin QHEs, candidates for applications in quantum technology due to their topological properties. For optimizing all these applications it is essential to understand where the current flows inside the Hall bar, a question disputed for decades. We perform multiterminal current measurements on a Hall bar and compare the results with limiting models. We confirm, based on these experiments, that the current flow is chiral for the plateaus of quantized Hall resistance. Everywhere else, including the ranges between plateaus, our results comply with the Drude model, which predicts homogeneous current flow across a homogeneous Hall-bar.

cond-mat.mes-hall↗

arXiv2025

Transition from edge- to bulk-currents in the quantum Hall regime

The integer quantum Hall effect can be observed in a two-dimensional conductor penetrated by a perpendicular magnetic field and with edges connecting the current carrying contacts. Its signature is a state of quantized Hall and simultaneously vanishing longitudinal resistances. A widely accepted model is the Landauer-Büttiker picture, which assumes an incompressible, i.e., electrically insulating bulk state surrounded by current carrying one-dimensional edge channels. This single-particle model is challenged by the screening theory. It derives, that electron-electron interaction leads to a fragmentation of the Hall bar into compressible and incompressible strips, where the current flows inside the incompressible strips. Because the latter gradually shift from the sample edges into the bulk as the magnetic field is increased, it suggests a transition from edge- to bulk-current. We present a direct experimental proof of this transition. Our results support the screening theory.

cond-mat.mes-hall↗