J. Phys. IV France
Volume 12, Numéro 9, November 2002
Page(s) 377 - 380

J. Phys. IV France
12 (2002) Pr9-377
DOI: 10.1051/jp4:20020442

Evidence for a liquid crystal phase transition in two-dimensional electrons in high Landau levels

K.B. Cooper1, M.P. Lilly1, J.P. Eisenstein1, L.N. Pfeiffer2 and K.W. West2

1  California Institute of Technology, Pasadena, CA 91125, U.S.A.
2  Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974, U.S.A.

Transport measurements of high-mohility two-dimensional electron systems at low temperatures have revealed a large resistance anisotropy around half-filling of excited Landau levels. These results have been attributed to electronic stripe-phase formation with spontaneously broken orientational symmetry. Mechanisms which are known to break the orientational symmetry include poorly-understood crystal structure effects and an in-plane magnetic field, B||. Here we report that a large B|| also causes the transport anisotropy to persist up to much higher temperatures. In this regime, we find that the anisotropic resistance scales sublinearly with B||/T. These observations support the proposal that the transition from anisotropic to isotropic transport reflects a liquid crystal phase transition where local stripe order persists even in the isotropic regime.

© EDP Sciences 2002