Scientists propose a fault-tolerant scheme for generating long-range entanglement at the ends of a rectangular array of qubits of length R.
It is realized by a constant-depth circuit producing a constant-fidelity Bell-pair (independent of R) for local stochastic noise of strength below an experimentally realistic threshold.
The scheme can be viewed as a quantum bus in a quantum computing architecture where qubits are arranged on a rectangular 3D grid, and all operations are between neighboring qubits.
Alternatively, it can be seen as a quantum repeater protocol along a line, with neighboring repeaters placed at a short distance to allow constant-fidelity nearest-neighbor operations.
npj Quantum Information, Published online: 26 December 2024; doi:10.1038/s41534-024-00928-4
