Quantum/Machines/IBM Loon
USA · operational · Superconducting circuits
IBM Loon
IBM Loon is a superconducting circuits quantum computer operated by IBM in USA. Its physical qubit count has not been published. 5 sourced specs are in the spec sheet. 1 published benchmark or milestone record are listed below, each marked by who measured it.
Also known as IBM Quantum Loon
Experimental IBM processor announced 12 November 2025 as a testbed for qLDPC error-correction components, including long-range on-chip connections and qubit reset. Quantum Computing Report describes it as unveiled and as demonstrating the key processor components needed for fault-tolerant quantum computing, so the operational status here means a demonstrated test chip, not a service. IBM says it was announced with real-time qLDPC decoding in under 480 nanoseconds on classical hardware. The sources consulted do not give a qubit count for Loon, and it is not listed among the devices on IBM's cloud compute page (checked 2026-10-13). It is a stepping stone toward IBM's planned Kookaburra (2026) and Starling (2029) systems.
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 | Loon, experimental processor for qLDPC error correction | Vendor reported | IBM says Loon shows the key processor components for fault-tolerant computing; no qubit count was given in the sources consulted. | newsroom.ibm.comquantumcomputingreport.com |
| Topology | Multiple low-loss routing layers giving c-couplers: long-range on-chip links beyond nearest neighbours | Vendor reported | IBM says c-couplers physically link distant qubits on the same chip and the chip includes qubit reset between computations. | newsroom.ibm.comnextplatform.com |
| Fabrication | IBM wafers at NY Creates Albany NanoTech Complex, 300 mm fab, New York | Vendor reported | Company-wide statement that primary quantum wafer fabrication is at Albany; the release does not name Loon specifically. | newsroom.ibm.comquantumcomputingreport.com |
| Successor | Kookaburra | Vendor reported | IBM roadmap places Kookaburra (2026) after Loon (2025), then Cockatoo (2027) and Starling (2029). | ibm.comspectrum.ieee.org |
| Roadmap | Kookaburra in 2026, Cockatoo in 2027, Starling fault-tolerant system in 2029 | Vendor reported | IBM roadmap blog of June 2025; the November 2025 release confirms Loon and the 2029 fault-tolerant target. | ibm.comthequantuminsider.com |
Milestone claims
- IBM, announcing Loon, claimed real-time qLDPC decoding in under 480 ns on classical hardware, a 10x speedup over leading approaches. (2025-11-12, vendor reported) quantumcomputingreport.comnextplatform.com
Timeline
- 2025-11-12: Announced
- 2025-11-12: Status checked: operational
More from IBM
- IBM Eagle (decommissioned, 127 qubits)
- IBM Osprey (decommissioned, 433 qubits)
- IBM Condor (operational, 1,121 qubits)
- IBM Heron (operational, 156 qubits)
- IBM Nighthawk (operational, 120 qubits)
- IBM Quantum System Two (Yorktown Heights) (operational)
- IBM Quantum Starling (planned)
- IBM Quantum System Two (Chicago) (under construction, 156 qubits)
- IBM Quantum System Two (Amaravati) (under construction, 156 qubits)
- IBM Quantum System One (Bromont) (operational, 127 qubits)
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 |
|---|---|---|---|
| Euro-Q-Exa | LRZ | 54 | operational |
| ORNL Pathfinder | Oak Ridge National Laboratory | 20 | operational |
| Rigetti Cepheus-1-108Q | Rigetti Computing | 108 | operational |
| Origin Wukong-180 | Origin Quantum | 180 | operational |
| IQM Radiance NOX at CINECA | CINECA | 54 | operational |
| IQM Radiance at Poznan University of Technology | Poznan University of Technology | - | operational |