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Stable quantum dots in an InSb two-dimensional electron gas

ORAL

Abstract

Indium antimonide (InSb) two-dimensional electron gases (2DEGs) have a unique combination of material properties: high electron mobility, strong spin-orbit interaction, large Landé g-factor, and small effective mass. This makes them an attractive platform to explore a variety of mesoscopic phenomena ranging from spintronics to topological superconductivity. However, there exist limited studies of quantum confined systems in these 2DEGs, often attributed to charge instabilities and gate drifts. We overcome this by removing the δ-doping layer from the heterostructure, and induce carriers electrostatically. This allows us to perform the first detailed study of stable gate-defined quantum dots in InSb 2DEGs. We demonstrate two distinct strategies for carrier confinement and study the charge stability of the dots. The small effective mass results in a relatively large single particle spacing, allowing for the observation of an even-odd variation in the addition energy. By tracking the Coulomb oscillations in a parallel magnetic field we determine the ground state spin configuration and show that the large g-factor (∼30) results in a singlet-triplet transition at magnetic fields as low as 0.3 T.

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Presenters

  • Ivan Kulesh

    Delft University of Technology

Authors

  • Ivan Kulesh

    Delft University of Technology

  • Chung-Ting Ke

    Delft University of Technology, QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Duke University

  • Candice Thomas

    Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, Purdue University, Microsoft Quantum at Station Q Purdue, Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University, Department of Physics and Astronomy and Station Q Purdue, Purdue University, Purdue University, Department of Physics and Astronomy and Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907 USA

  • Saurabh Karwal

    Netherlands Organization for Applied Scientific Research (TNO), QuTech and Netherlands Organization for Applied Scientific Research (TNO)

  • Christian Moehle

    Delft University of Technology, QuTech and Kavli Institute of Nanoscience, Delft University of Technology

  • Sara Metti

    Purdue University, Department of Physics and Astronomy and Station Q Purdue, Purdue University

  • Ray Kallaher

    Purdue University, Microsoft Quantum at Station Q Purdue, Purdue University

  • Geoffrey C. Gardner

    Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, Purdue University, Microsoft Quantum at Station Q Purdue, Materials Engineering, Purdue University, Purdue University, Microsoft Quantum at Station Q Purdue, Purdue University

  • Michael Manfra

    Physics and Astronomy, Purdue Univ, Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, School of Materials Engineering, School of Electrical and Computer Engineering, Purdue, Purdue Univ, Purdue University, Microsoft Quantum at Station Q Purdue, Department of Physics and Astronomy, Birck Nanotechnology Center, Microsoft Quantum Purdue, School og Materials Engineering & School of Electrical and Computer Engineering, P, Physics and Astronomy, Purdue University, Department of Physics and Astronomy and Station Q Purdue, Purdue University, Department of Physics and Astronomy and Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907 USA, Department of Physics and Astronomy, PURDUE UNIVERSITY, Department of Physics and Astronomy, Microsoft Quantum Purdue, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA, Physics, Purdue University

  • Srijit Goswami

    Delft University of Technology, QuTech and Kavli Institute of Nanoscience, Delft University of Technology