Quantum computers can get colder than deep space — Here's how they stay running

Heat disrupts the accuracy of a quantum computer, so the computer needs to be kept as cold as possible. Which is extremely cold, it turns out. Quantum computers can get colder than deep space — Here’s how they stay running.

Deep space sits at about 2.7 Kelvin (454.8 degrees below zero in Fahrenheit), in the leftover glow of the Big Bang. IBM’s latest modular cryogenic system is cooled below 15 millikelvin, which the company describes as more than 180 times colder than deep space. So how does IBM get a machine colder than deep space, and perhaps more importantly, why bother.

The answer starts with what’s being kept cold: the qubit. What is a qubit, and how does it differ from a bit. Regular computers calculate using bits: tiny switches that are either 1 or 0, on or off.

A qubit is closer to a dial than to a switch.