Anisotropic Quantum Hall effect

G.T. Einevoll, Department of Physics, University of California, San Diego, La Jolla, California 92093-0319
C.A. Lutken, NORDITA, Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark

Physical Review B 48, 11492-11495 (1993)

Abstract

A discussion of the transport properties of anisotropic Hall samples is presented. Such anisotropic samples can now be made by modulation-doped overgrowth on the cleaved edge of an Al_{x}Ga_{1-x}As compositional superlattice. The central issue here is the structure of the space of transport coefficients. We argue that the geometry and fixed-point structure of this parameter space, i.e., the global phase diagram of the anisotropic Hall system, follows from the same simple global symmetry which appears to govern the isotropic case. If the coordinates in parameter space are appropriately chosen the scaling diagram of the anisotropic system will coincide with the one for the isotropic case. Some of the many predictions following from this ansatz should be within experimental reach.