Unexplainable
Unexplainable

Oct 12, 2026 · 32 min

Quantum computers depend on an ultracold, scarce isotope

What’s cooler than being cool?

The quantum-computing race relies on elaborate refrigerators and a helium-3 supply whose limits could shape the technology’s future.

3 key takeaways
  1. 1Dilution refrigerators can create temperatures colder than deep space, enabling experiments near absolute zero.
  2. 2Quantum computers need extreme cooling because fragile qubits behave differently from ordinary bits under heat.
  3. 3Helium-3 makes ultracold cooling possible, but its scarcity ties quantum ambitions to nuclear stockpiles and lunar mining.

Don't miss

The episode reveals that helium-3 used in quantum refrigerators is largely obtained as a byproduct of decaying nuclear weapons, then considers mining it on the Moon.

The brief

Laboratories in Helsinki are building dilution refrigerators colder than deep space, turning a baseball-card-sized space into an extreme physics laboratory.

Zack Savitsky describes the enormous apparatus behind that tiny cold zone, while the episode explains why temperatures near absolute zero reveal unusual states of matter.

The payoff is quantum computing: delicate qubits require extreme cooling, making the field’s progress depend on infrastructure far beyond the processors themselves.

Dilution refrigerators use helium isotopes to remove heat, but helium-3 is rare and expensive; some systems require hundreds of thousands of dollars’ worth.

Much of the available helium-3 comes from decaying nuclear weapons, and a future shortage has researchers considering new production methods and even lunar mining.

Books & mentions

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Quantum computers depend on an ultracold, scarce isotope · PodLume