Observation of quantum Hall "valley Skyrmions".
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 nu = 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 nu = 1 are "valley Skyrmions."
Shkolnikov
Y P
YP
Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Misra
S
S
Bishop
N C
NC
De Poortere
E P
EP
Shayegan
M
M