Accurate spin and valley state identification in silicon double quantum dots

ORAL

Abstract

To read the state of silicon spin qubits, the mechanism that has provided highest fidelity is spin-to-charge conversion via Pauli spin blockade [1]. However, given the valley degree of freedom in silicon quantum dots, which can lead to complex energy spectra, accurate identification of the spin states involved in Pauli spin blockade is a key requirement for reliable readout and operation of silicon spin qubits.

Here, we expand the standard description of Pauli spin blockade in a double quantum dots (DQD) to include multiparticle states with large total spin angular momentum S. Using gate-based dispersive readout and magnetospectroscopy, we show successive steps of spin blockade and spin-blockade lifting involving spin states up to S=3 as well as the formation of a novel spin-quintet state [2]. Furthermore, we demonstrate the use of this technique for discerning whether the valleys involved in DQD interdot transitions are of equal or different quantum number.

[1] Harvey-Collard et al, Phys. Rev. X 8, 021046 (2018)
[2] Lundberg et al, Phys. Rev. X 10, 041010 (2020)

*Supported by EU’s Horizon 2020 Research and Innovation Programme, Engineering and Physical Sciences Research Council, Royal Society, Winton Programme for the Physics of Sustainability, and French National Research Agency.

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Presenters

  • Theodor Lundberg

    • Cavendish Laboratory, University of Cambridge

Authors

  • Theodor Lundberg

    • Cavendish Laboratory, University of Cambridge

  • David J. Ibberson

    • Quantum Engineering Technology Labs, University of Bristol

  • Jing LI

    • Université Grenoble Alpes, CEA, IRIG, MEM/L_Sim
    • Univ. Grenoble Alpes, CEA, IRIG-MEM-L Sim, F-38000, Grenoble, France
    • CEA, LETI, Minatec Campus, F-38054 Grenoble, France

  • Louis HUTIN

    • CEA/LETI-MINATEC, CEA-Grenoble
    • CEA Leti
    • CEA, Grenoble
    • CEA, LETI, Minatec Campus, F-38054 Grenoble, France

  • Benoit Bertrand

    • Leti, CEA
    • CEA/LETI-MINATEC, CEA-Grenoble
    • CEA, Grenoble
    • CEA, LETI, Minatec Campus, F-38054 Grenoble, France

  • Chang-Min Lee

    • Department of Materials Science and Metallurgy, University of Cambridge

  • David J. Niegemann

    • Institu Néel, CNRS
    • CNRS, Grenoble INP, Institut Néel, Université Grenoble Alpes

  • Matias Urdampilleta

    • Institu Néel, CNRS
    • CNRS, Grenoble INP, Institut Néel, Université Grenoble Alpes

  • Nadia A. Stelmashenko

    • Department of Materials Science and Metallurgy, University of Cambridge

  • Tristan Meunier

    • Institu Néel, CNRS
    • CNRS, Grenoble INP, Institut Néel, Université Grenoble Alpes

  • Jason Robinson

    • Department of Materials Science and Metallurgy, University of Cambridge

  • Maud Vinet

    • Leti, CEA
    • CEA/LETI-MINATEC, CEA-Grenoble
    • CEA Leti
    • CEA, Grenoble
    • CEA, LETI, Minatec Campus, F-38054 Grenoble, France

  • Lisa A. Ibberson

    • Hitachi Cambridge Laboratory
    • Hitachi Cambridge Laboratory, University of Cambridge
    • Hitachi Cambridge Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom

  • Yann-Michel Niquet

    • Université Grenoble Alpes, CEA, IRIG, MEM/L_Sim
    • Univ. Grenoble Alpes, CEA, IRIG-MEM-L Sim, F-38000, Grenoble, France
    • Université Grenoble Alpes, CEA, IRIG, MEM-L Sim, F-38000 Grenoble, France

  • M Fernando Gonzalez-Zalba

    • Quantum Motion Technologies
    • Hitachi Cambridge Laboratory
    • Hitachi Cambridge Laboratory, University of Cambridge
    • Quantum Motion Technologies, Nexus, Discovery Way, Leeds, LS2 3AA, United Kingdom