Berkeley Lab AQT 8-Qubit Ring

Berkeley Lab AQT 8-Qubit Ring is a superconducting circuits quantum computer operated by Lawrence Berkeley National Laboratory in USA. It has 8 physical qubits. It ranks 67 of 74 superconducting machines in this table by physical qubit count. 6 sourced specs are in the spec sheet. 5 published benchmark or milestone records are listed below, each marked by who measured it.

Also known as Advanced Quantum Testbed ring processor

Standard processor of the Advanced Quantum Testbed at Lawrence Berkeley National Laboratory, a DOE ASCR testbed announced in September 2018 (30 million dollars over five years, built with MIT Lincoln Laboratory) that gives free access to outside teams for published, non-proprietary work through competitive proposals. The AQT page, current as of August 2024, lists T1 and T2echo near 100 microseconds, CZ gates of about 200 ns with 0.5 to 1 percent error, and three-state readout above 95 percent. It does not state who fabricated this chip. Programme and chip are research tools, not a commercial service, and the page gives no 2026 status update.

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	8-qubit ring processor, the standard QPU of the Advanced Quantum Testbed	Vendor reported	Page current as of August 2024.	aqt.lbl.gov aqt.lbl.gov
Qubit type	transmon	Vendor reported	Frequencies 5.2 to 5.8 GHz with anharmonicity about 250 MHz.	aqt.lbl.gov
Topology	nearest-neighbor ring of 8 qubits	Vendor reported		aqt.lbl.gov
Native gates	X90 with virtual Z, cross-resonance CNOT, and CZ	Vendor reported	Cross-resonance CNOT takes 100 to 200 ns with 1 to 4 percent error; CZ about 200 ns with 0.5 to 1 percent error.	aqt.lbl.gov
Two-qubit gate time	200 ns	Vendor reported	CZ duration of about 200 ns; cross-resonance CNOT 100 to 200 ns.	aqt.lbl.gov
Access and pricing	Free proposal-based user programme for non-proprietary published work, typical projects weeks to months	Vendor reported	Funded by the DOE Office of Science ASCR programme.	aqt.lbl.gov newscenter.lbl.gov

Published benchmark figures

These are numbers the builder or a paper reports for this machine, not results from a common test. The basis column says who measured them. What the metrics mean and why they are not comparable across technologies.

Metric	Value	Measured	Basis	Note	Source
Readout fidelity	95%	2024-08	Vendor reported	Three-state readout fidelity stated as above 95 percent; value is a lower bound	aqt.lbl.gov
Single-qubit gate fidelity	99.95%	2024-08	Vendor reported	Isolated X90 error about 5e-4; 1 to 2e-3 when run simultaneously	aqt.lbl.gov
Energy relaxation time (T1)	100 µs	2024-08	Vendor reported	Approximate T1 of about 100 microseconds, with fluctuations	aqt.lbl.gov
Dephasing time (T2)	100 µs	2024-08	Vendor reported	T2echo of about 100 microseconds, with fluctuations	aqt.lbl.gov
Two-qubit gate fidelity	99%	2024-08	Vendor reported	CZ error 0.5 to 1 percent; value is the lower bound of the fidelity range (99.0 to 99.5)	aqt.lbl.gov

Timeline

2018-09: Announced
2024-08: Status checked: operational

Comparable superconducting machines

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

Machine	Operator	Qubits	Status
Aqumen Seeker	Quantum Circuits	8	operational
Rigetti Novera at Montana State University	Montana State University	9	operational
AWS Ocelot	Amazon	9	operational
Rigetti Novera at PSC (TangleLab)	PSC	9	planned
Rigetti Novera at University of Saskatchewan	University of Saskatchewan	9	operational
Horizon Quantum Testbed	Horizon Quantum Computing	9	operational