Abstract
Abstract
We present a universal quantum computing architecture which combines the measurement-driven aspect of MBQC with the circuit model’s algorithm dependent generation of qubit entanglement. Our architecture, which we call QGATE, is tailored for discrete-variable photonic quantum computers with deterministic photon sources capable of generating 1D entangled photonic states. QGATE achieves universal quantum computing on a logical data qubit register via the implementation of Clifford operations, QGATE ancilla, and arbitrary angle single-qubit measurements. We realise unitary evolutions defined by multi-qubit Pauli strings via the generation of entanglement between a sub-set of logical qubits and a mutual QGATE ancilla qubit. Measurement of the QGATE ancilla in the appropriate basis then implements a given term of the desired unitary operation. This enables QGATE to perform Hamiltonian evolutions in terms of a series of multi-qubit Pauli operators, a rule-based procedure for arbitrary Hamiltonians, or standard decomposition strategies to QGATE. We propose a photonic implementation of QGATE, calculating quantum error correction thresholds for fusion failure of 10.36 ± 0.02% and 25.98 ± 0.28% when deterministically generated 1D and 2D
entangled photonic qubit states respectively are used to construct logical qubits encoded using the foliated rotated surface code. Using 1D states, this puts the error tolerance on QGATE on a par with other comparable quantum computing architectures. The flexible approach of the photonic implementation of QGATE with its natural multi-qubit gates combined with deterministic entanglement generation via quantum emitters offers a promising building block for future advancements.