Magnetization measurements on a two-dimensional electron system

Abstract

We have measured the De Haas-Van Alphen oscillations in a 2D electron system of GaAs-(AlGa)As superlattices from 0 to 5 T at 1.5 K. The amplitude of the oscillations together with known density distribution implies for the Landau levels a half-width of ∼2 meV. which roughly agrees with the width calculated from the zero field mobility of 19000 cm 2 V · s . We have observed eddy current relaxation times up to 300 s at T ∼ 0.4 K suggesting the resistivity of the material at a quantized Hall plateau to be as low as ρ xx ≈- 10 −10 Ω/□ corresponding to a 3D resistivity of ρ ≈ 10 −16 Ω cm.