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Record-quality two-dimensional electron systems

ORAL

Abstract

We present our recent results on the growth of record-quality GaAs quantum wells via molecular beam epitaxy (MBE). These results were achieved by a careful purification and assessment of source material and vacuum quality, as well as innovation in MBE chamber design. Two-dimensional electron systems (2DESs) hosted in our new samples have a factor of ~2 higher mobility than the best previous 2DESs, with a peak mobility of electrons to μ = 44×106 cm2/Vs at an electron density of only n = 2×1011 /cm2. This is the highest mobility observed in any material. In representative samples with n ≈ 1×1011 /cm2, low temperature magnetotransport data display many-body states that have never been seen before. Furthermore, we find that the robustness of exotic interaction-driven states in these samples is unprecedented. For example, the ν = 5/2 fractional quantum Hall state shows an extraordinarily large activation gap of Δ = 820 mK, significantly larger than the previous record value of ~620 mK in samples with much larger electron densities of n ≈ 3×1011 /cm2.

Reference: Yoon Jang Chung, K. A. Villegas-Rosales, K. W. Baldwin, P. T. Madathil, K. W. West, M. Shayegan, L. N. Pfeiffer, arXiv:2010.02283.

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Presenters

  • Edwin Yoonjang Chung

    Princeton University

Authors

  • Edwin Yoonjang Chung

    Princeton University

  • K. A. Villegas-Rosales

    Princeton University

  • Kirk Baldwin

    Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University, Princeton University, Department of Electrical Engineering, Princeton University, Electrical Engineering, Princeton, Electrical Engineering, Princeton University

  • P. T. Madathil

    Princeton University

  • Ken W. West

    Princeton University, Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University, Department of Electrical Engineering, Princeton University, Electrical Engineering, Princeton, Electrical Engineering, Princeton University, Princeton

  • Mansour Shayegan

    Department of Electrical Engineering, Princeton University, Princeton University

  • Loren Pfeiffer

    Princeton University, Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University, Department of Electrical Engineering, Princeton University, Electrical Engineering, Princeton, Electrical Engineering, Princeton University, Princeton