Qubit
큐비트
The smallest unit of information in a quantum computer. It can be in a state that mixes 0 and 1.
Overview
A bit in an ordinary computer is either 0 or 1. A qubit can hold a mix of 0 and 1 in set proportions until it is measured. The moment you measure it, it settles on 0 or 1.
There are several ways to build qubits. Makers use super-cold superconducting circuits, ions trapped in an electric field, neutral atoms held by lasers, and particles of light (photons). Each method has its own strengths and weaknesses.
An everyday example
Picture a coin that has been tossed and is still spinning. While it spins, it is neither heads nor tails. The moment your hand catches it, it becomes one or the other.
Why it matters
News often says "a chip with so many qubits has been built." But to judge how good it really is, you also need to look at how few errors it makes, not just the number of qubits.
Also calledquantum bit