Abstract
In an AlAs quantum well where two-dimensional electrons occupy two conduction-band valleys with anisotropic Fermi contours, we tune the valley splitting energy via the application of strain and measure the energy gaps for the quantum-Hall state at filling factor ν=1. At zero valley splitting energy (strain), there is a sizeable energy gap which increases linearly with density. At a fixed density, the gap rises with increasing strain much faster than the single-particle picture predicts. Interpreting the rapid rise of the gap as a signature of valley Skyrmions, we find that their size grows as the electron density increases.
Original language | English (US) |
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Article number | 115336 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 81 |
Issue number | 11 |
DOIs | |
State | Published - Mar 31 2010 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics