Journal
PHYSICA E
Volume 6, Issue 1-4, Pages 87-90Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S1386-9477(99)00060-0
Keywords
FQHE; composite fermions; modulated 2DEGs
Ask authors/readers for more resources
We investigate the magnetoresistance of a weakly density modulated high mobility two-dimensional electron system around filling factor v = 1/2. The density modulation with periods a between 300 nm and 500 nm was generated by in situ interferometric illumination. At low B we found commensurability oscillations of the magnetoresistance characteristic for transport in weak electrostatic potentials with minima positions on the magnetic field axis given by 2R(C) = (lambda - 1/4)a. Here 2R(C) is the electron cyclotron diameter at the Fermi-energy and lambda an integer. In contrast, we find clear magnetic commensurability features around filling factor v = 1/2 with a pronounced minimum for a composite fermion cyclotron radius R-C,R-CF matching 1.25a. This gives direct evidence that the density modulation results in a modulated effective magnetic field for composite fermions. The experimental rho(xx)-traces around v = 1/2 are well described by novel model calculations, based on a semiclassical solution of the Boltzmann equation, taking into account anisotropic scattering. (C) 2000 Elsevier Science B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available