Observation of Quantum Hall Valley Skyrmions

Abstract

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".

4 pages, 3 figures

References in corpus (4)

• Low-temperature, in situ tunable, uniaxial stress measurements in semiconductors using a piezoelectric actuator
• The Two-flux Composite Fermion Series of Fractional Quantum Hall States in Strained Si
• Dependence of spin susceptibility of a two-dimensional electron system on the valley degree of freedom
• Giant low-temperature piezoresistance effect in AlAs two-dimensional electrons

Cited by in corpus (24)

• Landau Level Splitting in Graphene in High Magnetic Fields
• Valley susceptibility of an interacting two-dimensional electron system
• Graphene integer quantum Hall effect in the ferromagnetic and paramagnetic regimes
• Collective Modes and Skyrmion Excitations in Graphene SU(4) Quantum Hall Ferromagnets
• Observation of a Nematic Quantum Hall Liquid on the Surface of Bismuth
• Band mass anisotropy and the intrinsic metric of fractional quantum Hall systems
• Order from Disorder in Graphene Quantum Hall Ferromagnet
• Spontaneous Symmetry Breaking and Quantum Hall Effect in Graphene
• Angle dependence of the orbital magnetoresistance in bismuth
• Valley polarization and susceptibility of composite fermions around nu=3/2
• Nematic Valley Ordering in Quantum Hall Systems
• Observation of spontaneous valley polarization of itinerant electrons
• Entanglement Skyrmions in multicomponent quantum Hall systems
• Valley polarization assisted spin polarization in two dimensions
• Skyrme and Wigner crystals in graphene
• Band Collapse and the Quantum Hall Effect in Graphene
• Valley-Polarized quantum Hall phase in a strain-controlled Dirac system
• Robust Quantum Hall Ferromagnetism near a Gate-Tuned ν = 1 Landau Level Crossing
• Parallel Magnetic Field Tuning of Valley Splitting in AlAs Two-Dimensional Electrons
• Resonant optical topological Hall conductivity from skyrmions
• Dependence of persistent gaps at Landau level crossings on relative spin
• Donor binding energy and thermally activated persistent photoconductivity in high mobility (001) AlAs quantum wells
• Fractional quantum Hall valley ferromagnetism in the extreme quantum limit
• Spontaneous Breaking of the SU(3) Flavor Symmetry in a Quantum Hall Valley Nematic