--- title: IBM Connects Two 120-Qubit Processors With 99%... description: IBM researchers connected two 120-qubit Nighthawk R1 processors using four superconducting cables, showing a path toward modular quantum computers built from... canonical: https://daily.dev/posts/ibm-connects-two-120-qubit-processors-with-99-state-transfer-fidelity-iw3vqwqvh twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: IBM Connects Two 120-Qubit Processors With 99% State-Transfer Fidelity | daily.dev og:description: IBM researchers connected two 120-qubit Nighthawk R1 processors using four superconducting cables, showing a path toward modular quantum computers built from... og:url: https://daily.dev/posts/ibm-connects-two-120-qubit-processors-with-99-state-transfer-fidelity-iw3vqwqvh og:image: https://api.daily.dev/og/posts/iW3VqWQVH.png og:image:alt: IBM Connects Two 120-Qubit Processors With 99% State-Transfer Fidelity og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # IBM Connects Two 120-Qubit Processors With 99% State-Transfer Fidelity **[The Quantum Insider](https://daily.dev/sources/thequantuminsider)** · 8 min read · 0 upvotes · 0 comments ## Summary IBM researchers connected two 120-qubit Nighthawk R1 processors using four superconducting cables, showing a path toward modular quantum computers built from multiple chips. The links transferred quantum states with 99% average fidelity, with the best link hitting 99.29%. Full operations between processors, including controlled-Z gates used to create entanglement, averaged 94.75% fidelity. The team also entangled groups of four and six qubits across the chips and tested the links through three warm-up and cooldown cycles without failure. A modeled fix for qubit coherence could push state-transfer fidelity to 99.68-99.77%. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What fidelity did IBM achieve transferring quantum states between two separate quantum processors? IBM researchers achieved an average quantum state-transfer fidelity of 99% across four superconducting cable links connecting two 120-qubit Nighthawk R1 processors. All four links reached at least 98.86% fidelity, with the best link hitting 99.29% (uncertainty of 0.07 percentage points), measured using network benchmarking that separates transfer errors from state preparation and measurement errors. _Engineers tracking modular quantum hardware progress follow benchmark results like this on daily.dev._ ### How reliable are controlled-Z gate operations between qubits on different quantum chips? Complete controlled-Z gate operations between qubits on separate IBM Nighthawk R1 processors averaged 94.75% fidelity, with the best result reaching 96.42% (uncertainty of 0.28 percentage points). This is lower than pure state-transfer fidelity because the gate combines two state transfers, three local two-qubit gates, and additional single-qubit controls, introducing more opportunities for error. _Those weighing inter-chip quantum gate approaches can follow fidelity benchmarks like these on daily.dev._ ### What causes signal loss in superconducting cables used to link quantum processors? IBM researchers traced cable loss to magnetic fields present while the aluminum cable cooled into its superconducting state; the cable's ability to retain microwave energy declined substantially as that cooling-time magnetic field increased, and changing the field afterward did not reverse the effect. The team added two layers of magnetic shielding as a temporary mitigation, calling the underlying physical mechanism unresolved. _Researchers debugging superconducting hardware losses can track findings like this on daily.dev._ ## Similar posts on daily.dev - [Simultaneous high-fidelity single-qubit gates in a spin qubit array](https://daily.dev/posts/simultaneous-high-fidelity-single-qubit-gates-in-a-spin-qubit-array-k0lma6jad) · Nature · 0 upvotes · 0 comments - [IEEE-Presented Study Tests Quantum-to-Classical Handoff for Distributed Computing](https://daily.dev/posts/ieee-presented-study-tests-quantum-to-classical-handoff-for-distributed-computing-gcpx3rocm) · The Quantum Insider · 0 upvotes · 0 comments - [Breakthrough could connect quantum computers at 200X the distance](https://daily.dev/posts/breakthrough-could-connect-quantum-computers-at-200x-the-distance-qcirdifnd) · Phys.org · 2 upvotes · 0 comments - [Quantum Networking Beyond the Lab](https://daily.dev/posts/quantum-networking-beyond-the-lab-urd4afvut) · Cisco · 1 upvotes · 0 comments --- Tags: [#quantum-computing](https://daily.dev/tags/quantum-computing), [#ibm](https://daily.dev/tags/ibm) [View this post on daily.dev](https://daily.dev/posts/ibm-connects-two-120-qubit-processors-with-99-state-transfer-fidelity-iw3vqwqvh) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"IBM Connects Two 120-Qubit Processors With 99% State-Transfer Fidelity","url":"https://daily.dev/posts/ibm-connects-two-120-qubit-processors-with-99-state-transfer-fidelity-iw3vqwqvh","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/ibm-connects-two-120-qubit-processors-with-99-state-transfer-fidelity-iw3vqwqvh"},"datePublished":"2026-10-27T09:08:03.913Z","dateModified":"2026-10-27T09:08:33.599Z","description":"IBM researchers connected two 120-qubit Nighthawk R1 processors using four superconducting cables, showing a path toward modular quantum computers built from...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/5ec5401f9b348c552abbe457f6ff1432?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/5ec5401f9b348c552abbe457f6ff1432?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"The Quantum Insider","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"The Quantum Insider","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/7b14a6b34c1b464c9e8a88d9a0dac951","url":"https://daily.dev/sources/thequantuminsider"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/ibm-connects-two-120-qubit-processors-with-99-state-transfer-fidelity-iw3vqwqvh","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"quantum-computing,ibm","timeRequired":"PT8M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"The Quantum Insider","item":"https://daily.dev/sources/thequantuminsider"},{"@type":"ListItem","position":3,"name":"IBM Connects Two 120-Qubit Processors With 99% State-Transfer Fidelity"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/ibm-connects-two-120-qubit-processors-with-99-state-transfer-fidelity-iw3vqwqvh#faq","mainEntity":[{"@type":"Question","name":"What fidelity did IBM achieve transferring quantum states between two separate quantum processors?","acceptedAnswer":{"@type":"Answer","text":"IBM researchers achieved an average quantum state-transfer fidelity of 99% across four superconducting cable links connecting two 120-qubit Nighthawk R1 processors. 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