Phys.org December 10, 2024
Qubit connectivity on a planar surface is typically restricted to only a few neighboring qubits. Overcoming the complex multilayer packaging, external cabling, and fidelity limitations, a team of researchers in the US (University of Chicago, Argonne National Laboratory) proposed and developed a high-speed on-chip quantum processor that supported reconfigurable all-to-all coupling with a large on-off ratio. They implemented the design in a four-node quantum processor, built with a modular design comprising a wiring substrate coupled to two separate qubit-bearing substrates, each including two single-qubit nodes. Using the device they demonstrated reconfigurable controlled- gates across all qubit pairs, with average fidelity of 96.00% ±0.08% and best fidelity of 97.14% ±0.07%,. They generated multiqubit entanglement, distributed across the separate modules, demonstrating GHZ-3 and GHZ-4 states with high fidelities. According to the researchers their approach promises efficient scaling to larger-scale quantum circuits and offers a pathway for implementing quantum algorithms and error-correction schemes that benefit from enhanced qubit connectivity… read more. Open Access TECHNICAL ARTICLE
Multiqubit entanglement generation using one- and two-qubit gates… Credit:Â Physical Review X, 14, 041030.4 November, 2024