Commensurability oscillations in the rf conductivity of unidirectional lateral superlattices: measurement of anisotropic conductivity by coplanar waveguide

Abstract

We have measured the rf magnetoconductivity of unidirectional lateral superlattices (ULSLs) by detecting the attenuation of microwave through a coplanar waveguide placed on the surface. ULSL samples with the principal axis of the modulation perpendicular (S_perp) and parallel (S_||) to the microwave electric field are examined. For low microwave power, we observe expected anisotropic behavior of the commensurability oscillations (CO), with CO in samples S_perp and S_|| dominated by the diffusion and the collisional contributions, respectively. Amplitude modulation of the Shubnikov-de Haas oscillations is observed to be more prominent in sample S_||. The difference between the two samples is washed out with the increase of the microwave power, letting the diffusion contribution govern the CO in both samples. The failure of the intended directional selectivity in the conductivity measured with high microwave power is interpreted in terms of large-angle electron-phonon scattering.

8 pages, 5 figures

References in corpus (7)

• Melting of a 2D Quantum Electron Solid in High Magnetic Field
• Microwave Resonance of 2D Wigner Crystal around integer Landau fillings
• Evidence for Two Different Solid Phases of Two Dimensional Electrons in High Magnetic Fields
• Observation of pinning mode of stripe phases of 2D systems in high Landau levels
• Pinning mode resonances of 2D electron stripe phases: Effect of in-plane magnetic field
• Modulation of the Shubnikov-de Haas Oscillation in Unidirectional Lateral Superlattices
• Dependence of Modulation Amplitude on Electron Density in Unidirectional Lateral Superlattices: The Effect of the Thickness of the Two-dimensional Electron Gas

Cited by in corpus (6)

• Contactless Measurement of AC Conductance in Quantum Hall Structures
• Effect of Landau quantization on linear magnetoresistance of periodically modulated two-dimensional electron gas
• Nonlocality, Correlations, and Magnetotransport in a Spatially Modulated Two-Dimensional Electron Gas
• Anisotropic Behavior of the Thermoelectric Power and the Thermal Conductivity in a Unidirectional Lateral Superlattice: A Typical Anisotropic System Exhibiting Two Distinct Nernst Coefficients
• Universal Frequency Dependence of the Hopping AC Conductance in p-Ge/GeSi Structures in the Integer Quantum Hall Effect Regime
• Peltier cooling in Corbino-geometry quantum Hall systems