Low Frequency Admittance Measurements in the Quantum Hall Regime

Christophe Chaubet (1) , Carlos Hernandez (2)

1 L2C - Laboratoire Charles Coulomb
2 UNIANDES - Universidad de los Andes [Bogota]

In this paper we present an ac-magneto-transport study of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime, for frequencies in the range [100Hz, 1MHz]. We present an approach to understand admittance measurements based in the Landauer-Buttiker formalism for QHE edge channels and taking into account the capacitance and the topology of the cables connected to the contacts used in the measurements. Our model predicts an universal behavior with the a-dimensional parameter R H Cω where R H is the 2 wires resistance of the 2DEG, C the capacitance cables and the angular frequency, in agreement with experiments. For a specific configuration, we measure the electrochemical capacitance of the quantum Hall edge channels as predicted by Christen and Büttiker.

Domaines: Physique Quantique [quant-ph]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Christophe Chaubet, Carlos Hernandez. Low Frequency Admittance Measurements in the Quantum Hall Regime. 2013 IMRC Meeting, Aug 2013, Cancun, Mexico. pp.26, ⟨10.1557/opl.2013.1187⟩. ⟨hal-00933374⟩