the millikelvin · companion to the Deep · July 17, 2026

Two ways to build a
quantum computer

Google now bets on both. One is a chip in a giant refrigerator in Santa Barbara. The other is a grid of single atoms, held in light, in Boulder. Here is how the Boulder machine actually works, and why the giant wanted it.

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The strategy

Google's two-lane roadmap

For a decade Google chased one design. In March 2026 it added a second, and built it in Boulder. The two approaches solve the same problem in almost opposite ways.

Lane 1 · the incumbent

Superconducting

Santa Barbara · the Willow chip · ~10 years in
The qubitA tiny electrical circuit printed on a chip.
TemperatureNear absolute zero, in a house-sized dilution refrigerator.
LayoutFixed. Qubits are wired to their neighbors on the chip.
StrengthFast gates, deep engineering, a real error-correction milestone.
Boulder
Lane 2 · the new bet

Neutral atoms

Boulder · Adam Kaufman's team · new, ~10 people
The qubitA single real atom, identical to every other by nature.
TemperatureLaser-cooled atoms in a vacuum. No refrigerator at all.
LayoutReconfigurable. The atoms can be physically moved mid-computation.
StrengthMany identical qubits, flexible wiring, room to scale.
Same goal, opposite trades. Superconducting buys speed and maturity. Neutral atoms buy scale and flexibility. Google decided it wanted both. The rest of this page is Lane 2.

The machine

How a neutral-atom computer works

No chip, no fridge. Just atoms, laser light, and exquisite control. Four moves. Click through them.

One atom per trap of light. Nothing is touching them but photons.

Try it

A tweezer array, in your browser

This is a toy version of what Kaufman's team does for real: a grid of atoms held in light. Fire a Rydberg pulse to entangle neighbors. Rearrange to see why "the atoms can move" is the whole point.

atom qubitexcited to Rydberg stateentangled pair

In a real machine the atoms are ytterbium, cooled to a millionth of a degree and held by tightly focused lasers. Excite two neighbors into big, puffy Rydberg states and they feel each other strongly enough to entangle. That is the two-qubit gate. And because the traps are just light, you can pick atoms up and set them down somewhere else, rewiring the computer on the fly. Ytterbium has a bonus: the same atom that stores a qubit is also one of the best atomic clocks ever built.

why here

This is the physics Boulder perfected

Trapping single atoms in light, arranging them, and entangling them through Rydberg states was pioneered on the Front Range. Google did not invent this lane. It hired the people who did, and left them plugged into the labs that trained them. That is the story of the Deep.

Read the Deep: When the Giants Move In