Thermally activated deviations from quantum Hall plateaux

• Published in: Solid state communications 1995, Vol.94 (7), p.503-507
• Main Authors: Fogler, M.M., Shklovskii, B.I.
• Format: Article
• Language: English
• Subjects: A. semiconductors D. quantum Hall effect; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Physics; Quantum hall effect (including fractional)
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/0038-1098(95)00119-0

The Hall conductivity σ xy of a two-dimensional electron system is quantized in units of e 2 h when the Fermi level is located in the gap between two Landau levels. We consider the deviation of σ xy from a quantized value caused by the thermal activation of electrons to the extended states for the case of a long range random potential. This deviation is of the form σ xy ∗ exp( −Δ T ) . The prefactor σ xy ∗ is equal to e 2 h at temperatures above a characteristic value T 2. Below T 2, σ xy ∗ decays according to a power law: σ xy ∗ = e 2 h ( T T 2 ) γ . The generalization to fractional Hall plateaux is discussed.