Observation of Quantum Hall Valley Skyrmions

Shkolnikov, Y. P.; Misra, S.; Bishop, N. C.; De Poortere, E. P.; Shayegan, M.

Observation of Quantum Hall Valley Skyrmions

Authors

Description

We report measurements of the interaction-induced quantum Hall effect in a spin-polarized AlAs two-dimensional electron system where the electrons occupy two in-plane conduction band valleys. Via the application of in-plane strain, we tune the energies of these valleys and measure the energy gap of the quantum Hall state at filling factor $ν$ = 1. The gap has a finite value even at zero strain and, with strain, rises much faster than expected from a single-particle picture, suggesting that the lowest energy charged excitations at $ν=1$ are "valley Skyrmions".
4 pages, 3 figures