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arXiv · cond-mat/0003483

Reorientation of Anisotropy in a Square Well Quantum Hall Sample

W. Pan·T. Jungwirth·H. L. Stormer·D. C. Tsui·A. H. MacDonald·S. M. Girvin·L. Smrcka·L. N. Pfeiffer·K. W. Baldwin·K. W. West
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Abstract

We have measured magnetotransport at half-filled high Landau levels in a quantum well with two occupied electric subbands. We find resistivities that are {\em isotropic} in perpendicular magnetic field but become strongly {\em anisotropic} at $ν$ = 9/2 and 11/2 on tilting the field. The anisotropy appears at an in-plane field, $B_{ip} \sim$ 2.5T, with the easy-current direction {\em parallel} to $B_{ip}$ but rotates by 90$^{\circ}$ at $B_{ip} \sim$ 10T and points now in the same direction as in single-subband samples. This complex behavior is in quantitative agreement with theoretical calculations based on a unidirectional charge density wave state model.

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W. Pan, T. Jungwirth, H. L. Stormer, D. C. Tsui, A. H. MacDonald, S. M. Girvin, L. Smrcka, L. N. Pfeiffer, K. W. Baldwin, K. W. West. 2000-03-30. Reorientation of Anisotropy in a Square Well Quantum Hall Sample. https://doi.org/10.1103/physrevlett.85.3257

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