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Universal qubit control through FPGA-accelerated qubit classification, Hamiltonian estimation and real-time feedback [Part 1]

ORAL

Abstract

Gate-controlled spin qubits are a promising platform for implementing quantum processors [1,2] and now operate near the error-correctable threshold [3]. To correct errors, however, fast real-time feedback based on qubit measurements must be executed within the coherence time of the qubits. Moreover, continuous real-time feedback is also useful to tune and calibrate the qubit environment in order to maintain high fidelity gates and long coherence times.

Here, we read out singlet-triplet qubits in GaAs double quantum dots by radio-frequency reflectometry without analog demodulation/thresholding. Instead, qubit classification is performed in real-time on an FPGA-based pulse processor (Quantum Machines’ OPX+ [4]) using the raw reflectometry signal of the cryostat, opening the door to on-the-fly adaptive control sequences such as Hamiltonian estimation and qubit stabilization. To this end, we show how the co-integration of an OPX+ and QDevil’s QDAC [5] can be used to optimize qubit tuning voltages in real time, based on single-shot outcomes of qubit manipulations.



[1] A.M.J. Zwerver et al., Nat. Electron. 5, 184-190 (2022)

[2] S.G.J. Philips et al., Nature 609, 919-924 (2022)

[3] A. Noiri et al., Nature 601, 338–342 (2022)

[4] https://www.quantum-machines.co/opx+/

[5] https://qdevil.com/

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Presenters

  • Joost van der Heijden

    Quantum Machines, QDevil

Authors

  • Joost van der Heijden

    Quantum Machines, QDevil

  • Fabrizio Berritta

    Niels Bohr Institute, University of Copenhagen

  • Torbjørn R Rasmussen

    Niels Bohr Institute, University of Copenhagen

  • Fabio Ansaloni

    Quantum Machines, QDevil

  • Federico Fedele

    Niels Bohr Institute, University of Copenhagen, University of Oxford, University Of Oxford

  • Saeed Fallahi

    Purdue University, Microsoft Quantum Purdue, Physics and Astronomy, Purdue University, Purdue University

  • Geoff C Gardner

    Purdue University, Materials Engineering, Purdue University, Department of Physics and Astronomy, Birck Nanotechnology Center, Purdue University

  • Michael J Manfra

    Purdue University, Microsoft Quantum Purdue, Purdue University, Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA; Microsoft Quantum Lab, Purdue University, West Lafayette, IN, USA, Physics and Astronomy, Purdue University, Department of Physics and Astronomy, Birck Nanotechnology Center, School of Electrical and Computer Engineering and Microsoft Quantum Lab West Lafayette, Purdue University, Department of Physics and Astronomy and Nanotechnology Center Purdue University, Microsoft Quantum Lab West Lafayette, Department of Physics and Astronomy, Birck Nanotechnology Center, School of Materials Engineering and School of Electrical and Computer Engineering, Purdue University

  • Yonatan Cohen

    Quantum Machines

  • Jonatan Kutchinsky

    Quantum Machines, QDevil

  • Anasua Chatterjee

    Niels Bohr Institute, University of Copenhagen, Univ of Copenhagen

  • Ferdinand Kuemmeth

    Niels Bohr Institute, University of Copenhagen, Niels Bohr Institute, University of Copenhagen. Quantum Machines, QDevil, Niels Bohr Inst