Highly Coherent Nuclear and Electron Spin States in an Isotopically-Purified Semiconductor Diode

Solid-state spin defects are promising qubit candidates for quantum network technologies because of their ability to emit single photons and the ability to use nearby nuclear spins as a quantum memory resource [1]. Specifically, the neutrally-charged divacancy defect (VV₀) in silicon carbide (SiC) offers a near-infrared spin-photon interface [2], long coherence times[3], and a mature material platform with wafer-scale commercial availability. Recent results from isotopically-engineered SiC have demonstrated single-shot readout of the electronic spin of VV₀ and extended dephasing and decoherence times of VV₀, exceeding 5 seconds [4]. Leveraging these advantages of this platform, we measure record-long coherences of nearby nuclear spin qubits by mitigating dominant noise sources to demonstrate the benefits of isotopic growth and device integration [5]. These nuclear spin registers can be used as local memories to our optically-active VV₀. Using the same device, we then measure narrowed optical lines of VV₀ at the lifetime limit demonstrating similar charge noise mitigation. Our results will enable new pathways for highly coherent qubits in quantum information processing and sensing.

Ref:
[1] G. Wolfowicz, F. J. Heremans, C. P. Anderson et al., Nat. Rev. Mat. 6, 906-9256 (2021).
[2] D. J. Christle et al., Phys. Rev. X. 7, 1-12 (2017).
[3] H. Seo et al., Nat. Comm. 7, 12935 (2016).
[4] C. P. Anderson, E. O. Glen et al., Sci. Adv. 8, 5, eabm5912 (2022).
[5] C. Zeledon et al., in preparation (2025).

Work supported by the AFOSR and Boeing through the Chicago Quantum Exchange.