5/2 state in high election density gallium arsenide/aluminum gallium arsenide quantum well

This Master of Science Thesis is concerned with electronic transport in the higher Landau levels (LL) in a two-dimensional electron system, where novel many-body electronic phases have been observed. Particular attention is paid to the even-denominator fractional quantum Hall states at LL filling factors 5/2 and 7/2, and the anisotropic states at 9/2 and 11/2. In a high electron density (n = 6.3 x 10 11cm-2), high mobility (mu = 1 x 107cm2/Vs) modulation-doped GaAs/Al0.24Ga 0.76As quantum well, we observed the nu = 5/2 quantum Hall plateau at a high magnetic field B = 10 T. In contrast to previous findings in a lower density system, electronic transport at nu = 9/2 and nu = 11/2 is essentially isotropic. Anisotropic transport at 9/2 and 11/2 can be induced by an in-plane magnetic field, B//. Depending on the B// direction, the nu = 5/2 diagonal resistances in a high B// either remain isotropic or become strongly anisotropic. Our data suggest a new regime for electronic transport in higher LLs.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Natural Sciences

Grantor

Rice University

Year dc:date.issued

2010

Author dc:creator

• Zhang, Chi

Advisor dc:contributor.advisor

• Du, Rui-Rui

• Condensed matter physics

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/62186

OAI identifier oai:identifier

oai:repository.rice.edu:1911/62186