Possible anomalous Hall effect of Be/Si pair delta‐doped GaAs structures

Abstract

Beryllium/Silicon pair delta‐doped GaAs structures grown by molecular‐beam epitaxy exhibit Hall resistance which has highly nonlinear dependence on the applied magnetic field. The dependence of the occurrence of the nonlinear Hall resistance on the sample structure is investigated. A significantly large increase in the non‐linearity and magnitude of the Hall resistance is observed from a sample structure whose buffer layer is grown under the low As flux and thick buffer layer condition. The non‐linearity of the Hall resistance is found to depend on a single parameter B /T, where B and T are the magnetic field and temperature, respectively. From another sample structure in which an AlGaAs barrier with a single Be delta‐doped layer is placed near the Be/Si pair delta‐doped layer, a similar nonlinear Hall resistance is observed. On the basis of these results, it is suggested that the anomalous Hall effect results from interplay between itinerant holes in the valence band and localized spins in the delta‐doped layer in these structures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)