B Grade B

IBM Nighthawk r2: Physical qubits

120 qubits

As stated in the source: “120 programmable qubits, 218 couplers, 458 physical quantum elements in total”

Caveats

IBM's platform table lists 'Physical qubits 458' for ibm_phoenix (and 332 for Heron), which counts couplers and reset elements, not computational qubits. Use 120 as the qubit count; do not compare 458 with other vendors' qubit counts.

Set-up
ibm_phoenix. Square lattice, most qubits connected to four nearest neighbours; 218 tunable couplers plus 120 reset elements.
Method
Standard
Compared only with
results in the group “gate based”
Measured
Not stated
Published
31 August 2026
Measured by
IBM Quantum
Independent of the maker
No
Peer-reviewed
No
Repeated by others
Not yet

Source

IBM Quantum Nighthawk r2 (IBM Quantum blog), IBM Quantum (Holger Haas, David McKay, Robert Davis). Company technical document.

Comparable results

Machine ValueSet-upPublishedMeasured byGradeRecord
Quantinuum Helios 98 gate based 17 Jun 2026 Maker B r-000016
Quantinuum H2 56 gate based 2025 Maker B r-000022
Google Willow 105 gate based 9 Dec 2024 Maker B r-000008
Atom Computing Ytterbium atom array 256 gate based 18 Nov 2024 Maker B r-000036
IonQ Tempo 100 gate based – Maker B r-000026

History

Spotted a mistake? Report an error, quoting r-000015.