Jiuzhang 3.0

Jiuzhang 3.0 is a photonic quantum computer operated by USTC in China. Its physical qubit count has not been published. 6 sourced specs are in the spec sheet. 1 published benchmark or milestone record are listed below, each marked by who measured it.

USTC's third Jiuzhang photonic Gaussian boson sampling experiment, registering up to 255 photon-click events. It is a special-purpose sampler without a qubit count and was reported as a quantum computational advantage claim; the authors compare against Frontier. The claim concerns sampling a specific distribution rather than a useful computation.

Spec sheet

Technical details as the builder or a paper states them, each with its own source. A blank is a fact we could not source, not a zero. Fidelity and coherence figures are in the benchmark table below.

Spec	Value	Basis	Note	Source
Processor	Jiuzhang 3.0 Gaussian boson sampler: 25 squeezed sources, 144-mode interferometer, 144 SNSPDs	Peer reviewed	Paper later published in Physical Review Letters 131, 150601 (2023); overall linear efficiency of the setup is 43 percent.	arxiv.org journals.aps.org
Qubit type	Stimulated two-mode squeezed states from PPKTP crystals; photon-click sampling, no qubits	Peer reviewed	25 phase-locked two-mode squeezed state sources; squeezing parameters from 1.2 to 1.6 set by laser power.	arxiv.org journals.aps.org
Topology	Fully connected 144-mode ultralow-loss interferometer with 97 percent transmission	Peer reviewed	72 fibre loop units split each input into four time bins and two path bins to give pseudo-photon-number resolution.	arxiv.org journals.aps.org
Native gates	None (not gate-based): Gaussian boson sampling with pseudo-photon-number-resolving detection	Peer reviewed	It is a special-purpose sampler; detection uses 144 superconducting nanowire single-photon detectors behind fibre loops.	arxiv.org journals.aps.org
Predecessor	Jiuzhang 2.0	Independent	PostQuantum's table lists Jiuzhang 2.0 (2021, 144 modes) before Jiuzhang 3.0; Jiuzhang 2.0 is not in quantum_systems.csv.	postquantum.com
Successor	Jiuzhang 4.0	Independent	PostQuantum describes Jiuzhang 4.0 as the successor, with more than ten times the detected photons (3,050 versus 255).	postquantum.com

Milestone claims

USTC: up to 255 photon clicks; claims 1.27 us per sample vs ~600 years on Frontier for ideal sample generation (2023-04, peer reviewed) arxiv.org

Timeline

2023-04: Announced
2023-04: First operational
2023-04: Status checked: operational

Comparable photonic machines

Closest in physical qubit count within the same technology. Counts of different qubit types are not interchangeable across technologies.

Machine	Operator	Qubits	Status
Lucy	CEA	12	operational
Xanadu Aurora	Xanadu	12	operational
ORCA PT-2 at NQCC	National Quantum Computing Centre	-	operational
Jiuzhang 4.0	USTC	-	operational
Aegiq ARTEMIS at NQCC	National Quantum Computing Centre	-	operational
Quandela Belenos	Quandela	12	operational