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Scaling quantum systems with silicon carbide and molecules

Invited

Abstract

Scaling spin-based quantum technologies requires new platforms for creating and controlling quantum states. We begin with the divacancy defect (VV0) in silicon carbide (SiC), which combines long lived spin states with a tunable optical interface. First, we leverage the semiconducting host material by integrating single spin qubits into wafer-scale, commercial optoelectronic devices, enabling near terahertz-scale tuning and a mitigation of spectral diffusion in the defect’s optical structure [1].

We then discuss various strategies to extend the coherence of these spin qubits including isotopic purification, clock transitions, pulsed dynamical decoupling, and continuous driving to engineer a decoherence protected subspace [2,3]. These subspaces are decoupled from the major sources of noise, resulting in an over 10,000 times improvement in coherence [3]. Finally, we demonstrate the control and entanglement of a single nuclear spin with an electron spin in SiC. These nuclear memories can further extend coherence and enable multi-qubit quantum registers [2].

Optically addressable spin qubits can also be created, engineered, and scaled through a purely synthetic chemical approach. Moreover, these structures offer new opportunities to construct hybrid systems. We demonstrate the optical initialization and readout, and coherent control, of ground-state spins in organometallic molecules [4]. This bottom-up approach offers avenues to create designer qubits and to deploy the diverse capabilities of chemical synthesis for scalable quantum systems.

References:
[1] C. P. Anderson* and A. Bourassa* et al., Science 366, 6470, 1225-1230 (2019)
[2] A. Bourassa* and C. P. Anderson* et al., Nat. Mat. (2020), arXiv:2005.07602
[3] K. Miao et al., Science 369, 1493–1497 (2020)
[4] S. L. Bayliss*, D. W. Laorenza*, et al., arXiv:2004.07998 (2020)

In collaboration with: C. Anderson, A. Bourassa, K. Miao, S. Bayliss, D. Laorenza, G. Galli, D. Freedman

Presenters

  • David Awschalom

    University of Chicago, Pritzker School of Molecular Engineering, University of Chicago, Pritzker School for Molecular Engineering, University of Chicago, Center for Molecular Engineering, Materials Science Division, Argonne National Laboratory

Authors

  • David Awschalom

    University of Chicago, Pritzker School of Molecular Engineering, University of Chicago, Pritzker School for Molecular Engineering, University of Chicago, Center for Molecular Engineering, Materials Science Division, Argonne National Laboratory