Electronic devices in nuclear-spin free germanium heterostructures

ORAL

Abstract

Hole spin qubits are a promising platform for quantum computation, due to strong spin-orbit coupling allowing electrical qubit control. The p-symmetry in the hole wavefunction suppresses decoherence arising from hole-nuclear interactions, and experimental signatures of nuclear spin induced decoherence have been reported. Nuclear spin depleted 70Ge/28Si70Ge heterostructures are promising materials for realizing longer spin coherence times, but heterostructures with the required purity have not been available, to date. Here we present magnetotransport characterization of nuclear-spin-free Ge heterostructures on gated Hallbars, at hole concentrations between 0.7 × 10¹¹ cm⁻² to 1.25 × 10¹¹ cm⁻². We find a peak mobility of up to 220,000 cm²/Vs at a concentration of 1 × 10¹¹ cm⁻². We also discuss the effective hole masses in these heterostructures along with a comprehensive study of quantum scattering times. We present preliminary results on characterization of quantum dot devices fabricated in the 70Ge/28Si70Ge heterostructures.

*This work was undertaken with support from the Stewart Blusson Quantum Matter Institute (SBQMI), and the Canada First Research Excellence Fund, Quantum Materials and Future Technologies Program. JS acknowledges financial support from the National Science and Research Council of Canada (NSERC) in the Discovery Grant program and Quantum Alliance Consortium ``Consortium on Quantum Simulation with Spin Qubits'', and from Defence Canada (Innovation for Defence Excellence and Security, IDEaS). JS acknowledges financial support from the Canadian Foundation for Innovation (CFI) John Edwards Leaders Foundation and CFI Innovation Fund. ME acknowledges financial support from the NSERC CREATE in Quantum Computing Program (Grant Number 543245)

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Publication: Planning to submit for review end of October. Planned paper title: Isotopically pure 70Ge/28Si70Ge heterostructures grown on SiGe-buffered Si wafers

Presenters

  • Debojyoti Biswas

    • Stewart Blusson Quantum Matter Institute, University of British Columbia. Department of Physics and Astronomy, University of British Columbia

Authors

  • Debojyoti Biswas

    • Stewart Blusson Quantum Matter Institute, University of British Columbia. Department of Physics and Astronomy, University of British Columbia

  • Marcus S Edwards

    • Stewart Blusson Quantum Matter Institute, University of British Columbia. Department of Electrical and Computer Engineering, University of British Columbia

  • Mukhlasur R Tanvir

    • Stewart Blusson Quantum Matter Institute, University of British Columbia. Department of Electrical and Computer Engineering, University of British Columbia

  • Ebrahim Sajadi

    • Stewart Blusson Quantum Matter Institute, University of British Columbia

  • Patrick Daoust

    • Department of Engineering Physics, École Polytechnique de Montréal

  • Nicolas Rotaru

    • Department of Engineering Physics, École Polytechnique de Montréal

  • Alexis Dubé-Valade

    • Department of Engineering Physics, École Polytechnique de Montréal

  • Sebastian Koelling

    • Department of Engineering Physics, École Polytechnique de Montréal

  • Eloise Rahier

    • Department of Engineering Physics, École Polytechnique de Montréal

  • Patrick Del Vecchio

    • Ecole Polytechnique de Montreal

  • Oussama Moutanabbir

    • Polytechnique Montréal
    • Polytechnique Montreal
    • Department of Engineering Physics, École Polytechnique de Montréal

  • Joseph Salfi

    • Stewart Blusson Quantum Matter Institute, University of British Columbia. Department of Electrical and Computer Engineering, University of British Columbia