Two-dimensional electrons in spatially inhomogeneous magnetic field

Two-dimensional electron gas (2DEG) subjected to a spatially modulated magnetic field exhibits commensurability oscillation of magnetoresistance, analysis of which furnishes information on the modulation amplitude. Under a periodically modulated magnetic field with zero mean, the resistivity of the 2DEG gains an extra term expressed as Δρ=AT2+C. The temperature quadratic term is attributed to electron–electron umklapp scattering, while the constant term arises from combined effect of the lateral magnetic superlattice and random impurities. In the composite Fermion (CF) regime near the half-filling of lowest Landau levels, spatial variation of the electron density is equivalent to magnetic field variation. Use of a short period lateral superlattice has enabled us to observe the commensurability oscillation of the magnetoresistance of CFs near the filling factor ν=3/2. The positions of the resistance minima are consistent with those calculated by assuming magnetic modulation and fully spin-polarized CFs.