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arXiv · 1408.3849

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

Mohammad Samani·Alexander V. Rossokhaty·Ebrahim Sajadi·Silvia Lüscher·Joshua A. Folk·John D. Watson·Geoffrey C. Gardner·Michael J. Manfra
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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.

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Mohammad Samani, Alexander V. Rossokhaty, Ebrahim Sajadi, Silvia Lüscher, Joshua A. Folk, John D. Watson, Geoffrey C. Gardner, Michael J. Manfra. 2014-08-17. Low-temperature illumination and annealing of ultra-high quality quantum wells. https://doi.org/10.1103/physrevb.90.121405

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