Geometric resonances in the magnetoresistance of hexagonal lateral superlattices
arXiv:1208.4480 · doi:10.1103/PhysRevB.86.235315
Abstract
We have measured magnetoresistance of hexagonal lateral superlattices. We observe three types of oscillations engendered by periodic potential modulation having hexagonal-lattice symmetry: amplitude modulation of the Shubnikov-de Haas oscillations, commensurability oscillations, and the geometric resonances of open orbits generated by Bragg reflections. The latter two reveal the presence of two characteristic periodicities, sqrt{3} a / 2 and a / 2, inherent in a hexagonal lattice with the lattice constant a. The formation of the hexagonal-superlattice minibands manifested by the observation of open orbits marks the first step toward realizing massless Dirac fermions in semiconductor 2DEGs.
arXiv comment11 pages, 9 figures, minor revision
References in corpus (22)
- Energy gaps, topological insulator state and zero-field quantum Hall effect in graphene by strain engineering
- Charge Density Wave in Two-Dimensional Electron Liquid in Weak Magnetic Field
- The Ground State of a Two-Dimensional Electron Liquid in a Weak Magnetic Field
- Exact results for interacting electrons in high Landau levels
- Engineering artificial graphene in a two-dimensional electron gas
- Making Massless Dirac Fermions from Patterned Two-Dimensional Electron Gases
- New insulating phases of two-dimensional electrons in high Landau levels: observation of sharp thresholds to conduction
- Spontaneous Breakdown of Translational Symmetry in Quantum Hall Systems: Crystalline Order in High Landau Levels
- From laterally modulated two-dimensional electron gas towards artificial graphene
- Microwave resonances of the bubble phases in 1/4 and 3/4 filled higher Landau levels
- Weiss oscillations in the presence of small-angle impurity scattering
- Delocalized-localized transition in a semiconductor two-dimensional honeycomb lattice
- Commensurability oscillations due to pinned and drifting orbits in a two-dimensional lateral surface superlattice
- Origin of positive magnetoresistance in small-amplitude unidirectional lateral superlattices
- Harmonic Content of Strain-induced Potential Modulation in Unidirectional Lateral Superlattices
- New class of small amplitude low-field magnetoresistance oscillation in unidirectional lateral superlattice: Geometric resonance of Bragg-reflected cyclotron orbit
- Commensurability Effects in Hexagonal Antidot Lattices with Large Antidot Diameters
- Inverse flux quantum periodicity of magnetoresistance oscillations in two-dimensional short-period surface superlattices
- Modulation of the Shubnikov-de Haas Oscillation in Unidirectional Lateral Superlattices
- Anisotropic transport in unidirectional lateral superlattice around half-filling of the second Landau level
- Fourier analyses of commensurability oscillations in Fibonacci lateral superlattices
- Higher order terms in the geometric resonance of open orbits in unidirectional lateral superlattices