Readout and coherent control of precision atom qubits in isotopically pure silicon*

The ability to address and individually control nuclear spins in solid state systems [1,2] has established them amongst the most promising platforms for quantum information science. Nuclear spin qubits in silicon in particular have demonstrated the longest coherence times by isotopically purifying the silicon host material, thereby eliminating the most dominant decoherence mechanism [3]. Here we demonstrate single-shot spin readout and control of multiple nuclear spins in precision engineered multi-donor quantum dot qubits [4,5] realised in 210 ppm isotopically pure Si-28. This work demonstrates the advantages of multiple donor nuclei in the operation of donor-based qubits.

[1] J. J. Pla et.al., High-fidelity readout and control of a nuclear spin qubit in silicon Nature 496, 334 (2013).

[2] M. V. Gurudev Dutt et. al, Science 316, 1312 (2007).

[3] J. T. Muhonen et.al, Storing quantum information for 30 seconds in a nanoelectronic device, Nature Nanotechnology 9, 986–991 (2014).

[4] Y. He et.al. A two-qubit gate between phosphorus donor electrons in silicon, Nature 571, 371 (2019).

[5] L. Fricke et.al., Coherent control of a donor-molecule electron spin qubit in silicon, Nat. Commun. 12, 3323 (2021)