# Quantum Infrastructure (DD-012) > The gold 'chandelier' in photos of quantum computers is really a refrigerator. Superconducting qubits are so easily disturbed that the chip sits on the bottom plate of a dilution refrigerator. Each stage of the fridge is colder than the one above, and the bottom plate is held around 10–15 millikelvin by a mixture of helium-3 and helium-4. That is more than 180 times colder than the 2.7 K of deep space. - Department: Science (also Tech) - First published: 2026-06-13 - Last updated: 2026-06-13 - Permalink: https://detailenjoyer.com/case/quantum-cryogenics/ - Author: Marcus Easterling (DetailEnjoyer), The Detail Department ## On the timeline - **August 2026**: IBM joins two cryogenic modules into one ultra-cold environment Full timeline: https://detailenjoyer.com/timeline/?case=quantum-cryogenics ## Quick facts - **DD-012-F01**: A superconducting quantum chip sits on the bottom plate of a dilution refrigerator at around 10–15 millikelvin, more than 180 times colder than deep space. _(Write-up · Exhibit F (Colder than deep space))_ - **DD-012-F02**: Dilution refrigerators cool by pumping helium-3 across the boundary between two phases of a helium-3/helium-4 mixture, which only separates below about 0.87 K. _(Write-up · Exhibit D (Helium-3 meets helium-4))_ ## Write-up This golden chandelier keeps qubits colder than outer space. A dilution refrigerator chills the chip to about 10–20 thousandths of a degree above absolute zero. 1. **Fragile by design**: Qubits must be almost perfectly isolated from heat, vibration and stray disturbances. Even then, they hold their quantum states for at most a few hundred microseconds before they 'decohere'. 2. **The 'chandelier' is a fridge**: The tiered gold structure is a dilution refrigerator. It has a stack of metal plates, each colder than the one above, with the top plate at room temperature. 3. **Chip at the bottom**: The quantum processor is mounted on the lowest and coldest plate, the mixing chamber. It sits inside a shielded package that blocks stray radiation and magnetic fields. 4. **Helium-3 meets helium-4**: Below about 0.87 K, a mixture of helium-3 and helium-4 separates into two phases. Pumping helium-3 across the boundary between them absorbs heat, like evaporation, and this provides continuous cooling. 5. **About 10–15 thousandths of a degree**: Commercial dilution refrigerators reach a base temperature of around 10 mK. IBM's fridges hold chips at about 10–15 mK. 6. **Colder than deep space**: Space is bathed in the 2.7 K cosmic microwave background. IBM says its fridges, at below 15 mK, are more than 180 times colder than deep space. 7. **Getting bigger**: In August 2026, IBM joined two cryogenic modules, each over 8 feet tall and wide, into one ultra-cold environment. The modules are designed to link hundreds of quantum chips. ## Related case files - [Data Centers (DD-029)](https://detailenjoyer.com/case/data-centers/): Another extreme cooling problem in computing. - [Stellar Birth (DD-037)](https://detailenjoyer.com/case/stellar-birth/): The other extreme of cold, near absolute zero. - [Casimir's Effect (DD-618)](https://detailenjoyer.com/case/casimirs-effect/): Another case about superconducting quantum circuits - [Atomic Stop-motion (DD-663)](https://detailenjoyer.com/case/atomic-stop-motion/): IBM's ultra-cold hardware for quantum chips - [Hefei Fusion (DD-738)](https://detailenjoyer.com/case/hefei-fusion/): More superconducting hardware: quantum computers chilled to 10–20 thousandths of a degree above absolute zero. - [Cosmic Freezer (DD-752)](https://detailenjoyer.com/case/coldest-place-universe-v2/): I linked the fridges that chase temperatures near absolute zero on Earth ## Reel vs. record - **Confirmed**: the cryogenic stack protects qubits from heat, vibration and electromagnetic interference; the processor is mounted at the bottom; and the fridge cools with a He-3/He-4 mixture. [Bluefors; Oxford; PRX Quantum; Popular Science; MIT Tech Review] - **Range check**: '10–20 mK' is fair. Base temperatures are typically ≤10 mK, with qubits operated around 10–15 mK. 'Colder than outer space' is correct (deep space is about 2.7 K). [PRX Quantum; Popular Science; IBM] - **Nuance**: this applies to superconducting qubits, as the Reel says. Other kinds of quantum computers, such as trapped-ion and photonic, don't need a dilution refrigerator for the qubits themselves. ## Video: Quantum Infrastructure: This Golden Chandelier Keeps Qubits Colder Than Outer Space - Duration: 26.5 s · Published: 2026-06-13 - File: https://detailenjoyer.com/assets/videos/DZjIL-VRx8M.mp4 ### Transcript DID YOU KNOW? A modern quantum computer is built around an intricate cryogenic architecture designed to protect its extremely fragile qubits from heat, vibration, and electromagnetic interference. In superconducting systems, the quantum processor is mounted at the bottom of a towering dilution refrigerator, a multi-stage cooling apparatus that uses mixtures of helium-3 and helium-4 to reach temperatures of around 10-20 mK, colder than outer space and just a fraction of a degree above absolute zero. NOW YOU KNOW! ## Questions & answers **Q: What is the gold 'chandelier' seen in photos of quantum computers?** A: It's a multi-stage dilution refrigerator, and each plate down is colder. _(Source: Write-up · Exhibit B (The 'chandelier' is a fridge) · An in-depth look at an IBM quantum computer (Popular Science); How Does a Dilution Refrigerator Work? (Bluefors))_ **Q: Where in the fridge does the quantum chip sit?** A: The processor is mounted on the mixing-chamber plate, the coldest stage, at the bottom. _(Source: Write-up · Exhibit C (Chip at the bottom) · Microwave Package Design for Superconducting Quantum Processors (PRX Quantum 2, 020306, 2021); An in-depth look at an IBM quantum computer (Popular Science))_ **Q: Which two substances does a dilution refrigerator use?** A: It uses the heat of mixing of the two helium isotopes. _(Source: Write-up · Exhibit D (Helium-3 meets helium-4) · 3He/4He Dilution Refrigerators (University of Oxford, Physics); How Does a Dilution Refrigerator Work? (Bluefors))_ **Q: Roughly how cold do superconducting qubits get?** A: Around 10–15 mK, a fraction of a degree above absolute zero. _(Source: Write-up · Exhibit E (About 10–15 thousandths of a degree) · Microwave Package Design for Superconducting Quantum Processors (PRX Quantum 2, 020306, 2021); An in-depth look at an IBM quantum computer (Popular Science); How Does a Dilution Refrigerator Work? (Bluefors))_ **Q: How does that compare with deep space (about 2.7 K)?** A: IBM says its sub-15 mK fridges are more than 180 times colder than deep space. _(Source: Write-up · Exhibit F (Colder than deep space) · IBM Connects Its First Modular Cryogenic Systems (IBM Newsroom, Aug 19, 2026); An in-depth look at an IBM quantum computer (Popular Science))_ ## Sources - [How Does a Dilution Refrigerator Work? (Bluefors)](https://bluefors.com/stories/how-does-a-dilution-refrigerator-work/) - [3He/4He Dilution Refrigerators (University of Oxford, Physics)](https://www-nog.physics.ox.ac.uk/www/fridge/fridge.html) - [Microwave Package Design for Superconducting Quantum Processors (PRX Quantum 2, 020306, 2021)](https://journals.aps.org/prxquantum/pdf/10.1103/PRXQuantum.2.020306) - [An in-depth look at an IBM quantum computer (Popular Science)](https://www.popsci.com/technology/in-photos-journey-to-the-center-of-a-quantum-computer/) - [IBM Connects Its First Modular Cryogenic Systems (IBM Newsroom, Aug 19, 2026)](https://newsroom.ibm.com/2026-08-19-ibm-connects-its-first-modular-cryogenic-systems-in-milestone-toward-fault-tolerant-quantum-computing) - [Inside the race to build the best quantum computer on Earth (MIT Technology Review, 2020)](https://www.technologyreview.com/2020/02/26/916744/quantum-computer-race-ibm-google/) ## Cite this case file Easterling, Marcus. "Quantum Infrastructure." The Detail Department (DetailEnjoyer), case file DD-012, last updated Jun 13, 2026. https://detailenjoyer.com/case/quantum-cryogenics/