IBM has one-upped AWS and Microsoft by reporting an outage in one of its cloudy quantum computers.

Early on Thursday morning, Big Blue [1]advised “The quantum computer, ibm_aachen, is temporarily unavailable within the Qiskit Runtime service.”

The advisory says IBM is “actively working to restore this quantum computer to service as soon as possible.”

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The Qiskit Runtime is a cloud service that allows IBM customers to use its quantum processors.

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In April 2025, IBM Germany managing director for R&D David Waller [5]announced the Aachen system had come online in the Big Blue cloud, and gave users the chance to tap “156 qubits of the Heron r2 processor generation.”

IBM’s announcement is very brief and offers no hint of what’s awry with the Aachen system.

[6]

While Big Blue has productized its quantum machines, they remain finicky. One reason for that is that even when working well they’re not fault-tolerant, so they can produce errors or just fail to finish a job. Another is that it’s hard to maintain a qubit in a stable state. Changes in temperature or an unexpected encounter with a magnetic field can cause “quantum decoherence” – a condition in which it’s even harder to maintain a superposition or quantum entanglement, and therefore hard to run any computing workloads.

Commercial quantum computers use lots of shielding and physical protections to keep qubits in a useful state. It appears those measures couldn’t keep the Aachen machine happy at IBM’s European Quantum Data Center near the German city of Stuttgart.

[7]Bitter fight over 2020 Microsoft quantum paper both resolved and unresolved

[8]Cloudflare Q3 report shows the internet still breaks for the strangest reasons

[9]Vodafone keels over, cutting off millions of mobile and broadband customers

[10]IBM quantum system elbows into Arm-powered Fugaku supercomputer

Users of quantum computers know the tech is in its infancy so may well tolerate downtime.

Those users will also know that the likes of Microsoft and AWS claim to be masters of anti-fragility and resilience in their classical clouds.

Yet both experienced outages in recent days, with Microsoft on Wednesday [11]admitting to problems with its content delivery network that have impacted airlines and other users.

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AWS had an even bigger outage [13]last week and on Tuesday delivered a [14]sequel .

A common technique to fix a classical computer is turning it off, then on again. The Register suspects that won’t do the trick for a quantum machine. If you know better, hit the comments below. ®

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[1] https://cloud.ibm.com/status/announcement?query=The+quantum+computer%2C+ibm_aachen%2C+is+temporarily+unavailable+within+the+Qiskit+Runtime+service

[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offprem/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aQNFRj1V_92EvQB8faAYyQAAAYI&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offprem/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aQNFRj1V_92EvQB8faAYyQAAAYI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offprem/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aQNFRj1V_92EvQB8faAYyQAAAYI&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[5] https://www.linkedin.com/posts/dfaller_heron-ibm-quantum-activity-7317587221140619265-yiDs/

[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offprem/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aQNFRj1V_92EvQB8faAYyQAAAYI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[7] https://www.theregister.com/2025/07/31/microsoft_quantum_paper_science/

[8] https://www.theregister.com/2025/10/28/cloudflare_q3_internet_disruption/

[9] https://www.theregister.com/2025/10/13/vodafone_outage/

[10] https://www.theregister.com/2024/04/30/fugaku_supercomputer_ibm_quantum_module/

[11] https://www.theregister.com/2025/10/29/microsoft_azure_outage/

[12] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offprem/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aQNFRj1V_92EvQB8faAYyQAAAYI&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[13] https://www.theregister.com/2025/10/20/amazon_aws_outage/

[14] https://www.theregister.com/2025/10/29/aws_us_east_1_more_problems/

[15] https://whitepapers.theregister.com/