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Quantum Infrastructure

Short answer: 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.

VideoWrite-up6 sources

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What should you know about Quantum Infrastructure?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. 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.

    DD-012-F01 · Write-up · Exhibit F (Colder than deep space)

  2. 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.

    DD-012-F02 · Write-up · Exhibit D (Helium-3 meets helium-4)

Video transcript: Quantum Infrastructure: This Golden Chandelier Keeps Qubits Colder Than Outer Space

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!

Burned-in captions, read frame by frame (see transcript.md) · 26.5s Reel ·

Video coming soonQuantum Infrastructure · Instagram Reel
Quantum Infrastructure: This Golden Chandelier Keeps Qubits Colder Than Outer Space Instagram Reel · · 26.5s

The 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. Exhibit A

    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. Exhibit B

    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. Exhibit C

    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. Exhibit D

    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. Exhibit E

    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. Exhibit F

    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. Exhibit G

    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.

Questions people ask about Quantum Infrastructure

What is the gold 'chandelier' seen in photos of quantum computers?

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)

Where in the fridge does the quantum chip sit?

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)

Which two substances does a dilution refrigerator use?

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)

Roughly how cold do superconducting qubits get?

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)

How does that compare with deep space (about 2.7 K)?

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)

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. What is the gold 'chandelier' seen in photos of quantum computers?

    1. A dilution refrigerator
    2. A cooling fan array
    3. The quantum processor itself
    4. A power supply
    Show the answer

    Answer: A. A dilution refrigerator 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)

  2. Where in the fridge does the quantum chip sit?

    1. At the top, at room temperature
    2. In the middle
    3. At the bottom, on the coldest plate
    4. Outside the fridge
    Show the answer

    Answer: C. At the bottom, on the coldest plate 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)

  3. Which two substances does a dilution refrigerator use?

    1. Liquid nitrogen and oxygen
    2. Helium-3 and helium-4
    3. Hydrogen and helium
    4. Argon and neon
    Show the answer

    Answer: B. Helium-3 and helium-4 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)

  4. Roughly how cold do superconducting qubits get?

    1. About 77 K
    2. About 4 K
    3. About 10–15 millikelvin
    4. Exactly 0 K
    Show the answer

    Answer: C. About 10–15 millikelvin 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)

  5. How does that compare with deep space (about 2.7 K)?

    1. About the same
    2. Roughly twice as cold
    3. More than 180 times colder
    4. Slightly warmer
    Show the answer

    Answer: C. More than 180 times colder 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)

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/

Permalink: https://detailenjoyer.com/case/quantum-cryogenics/ · Last updated

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Cite a single fact by its ID, for example DD-012-F01 → https://detailenjoyer.com/case/quantum-cryogenics/#DD-012-F01

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