Low-temperature illumination and annealing of ultra-high quality quantum wells

Abstract

The effects of low temperature illumination and annealing on fractional quantum Hall (FQH) characteristics of a GaAs/AlGaAs quantum well are investigated. Illumination alone, below 1 K, decreases the density of the 2DEG electrons by more than an order of magnitude and resets the sample to a repeatable initial state. Subsequent thermal annealing at a few Kelvin restores the original density and dramatically improves FQH characteristics. A reliable illumination and annealing recipe is developed that yields an energy gap of 600 mK for the 5/2 state.

References in corpus (6)

• Insulating and Fractional Quantum Hall States in the N=1 Landau Level
• Non-Abelian quantized Hall states of electrons at filling factors 12/5 and 13/5 in the first excited Landau level
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• Increasing the ν = 5 / 2 gap energy: an analysis of MBE growth parameters
• A new type of carbon resistance thermometer with excellent thermal contact at millikelvin temperatures

Cited by in corpus (16)

• Observation of half-integer thermal Hall conductance
• Modified MBE hardware and techniques and role of gallium purity for attainment of two dimensional electron gas mobility >35 x10^6 cm^2/Vs in AlGaAs/GaAs quantum wells grown by MBE
• Zero-Magnetic Field Fractional Quantum States
• Quantum Lifetime in Ultra-High Quality GaAs Quantum Wells: Relationship to ${\Delta }_{5/2}$ and Impact of Density Fluctuations
• Edge Probes of Topological Order
• Reorientation of quantum Hall stripes within a partially filled Landau level
• Impact of Heterostructure Design on Transport Properties in the Second Landau Level of in-situ Back-Gated Two-Dimensional Electron Gases
• Observation of an anomalous density-dependent energy gap of the $\nu =5/2$ fractional quantum Hall state in the low density regime
• Working principles of doping-well structures for high-mobility two-dimensional electron systems
• Spatial Mapping of Local Density Variations in Two-dimensional Electron Systems Using Scanning Photoluminescence
• Anomalous Nematic States in High Half-Filled Landau Levels
• Electron-Hole Asymmetric Chiral Breakdown of Reentrant Quantum Hall States
• Spatially resolved breakdown in reentrant quantum Hall states
• High temperature resistivity measured at ν = 5/2 as a predictor of 2DEG quality in the N=1 Landau level
• Effect of illumination on quantum lifetime in GaAs quantum wells
• Exploring Quantum Hall Physics at Ultra-Low Temperatures and at High Pressures