npj Quantum Information, Published online: 02 November 2024; doi:10.1038/s41534-024-00898-7
An architecture for two-qubit encoding in neutral ytterbium-171 atoms
In this paper, researchers present an architecture for encoding two qubits within the optical “clock” transition and nuclear spin-1/2 degree of freedom of neutral ytterbium-171 atoms.
Inspired by recent high-fidelity control of all pairs of states within this four-dimensional quotes space, they present a toolbox for intra-ququart (single-atom) one- and two-qubit gates, inter-ququart (two-atom) Rydberg-based two- and four-qubit gates, and quantum nondemolition (QND) readout.
They have used this toolbox to demonstrate the advantages of the ququart encoding for entanglement distillation and quantum error correction which exhibit superior hardware efficiency and better performance in some cases since fewer two-atom operations are required.
Finally, leveraging single-state QND readout in our ququart encoding, they present a unique approach to studying interactive circuits and to realizing a symmetry protected topological phase of a spin-1 chain with a shallow, constant-depth circuit.
