qubit

noun

qu·​bit ˈkyü-bət 

plural qubits

: a unit of computing information that is represented by a state of an atom or elementary particle (such as the spin) and can store multiple values at once due to the principles of quantum mechanics

And the most basic truth of quantum mechanics dictates that you cannot measure a qubit without destroying the superposition. The register that said 1 and 0 will randomly collapse into 1 or 0.

—George Johnson

compare bit entry 3 sense 1

Examples of qubit in a Sentence

Recent Examples on the Web

These cat qubits are miniscule hollow structures of tantalum containing microwave radiation. —New Atlas, 28 Feb. 2025

The company’s aim is to create a machine built of a million qubits. —Paul Smaglik, Discover Magazine, 20 Feb. 2025

And as the number of qubits grows, a quantum computer becomes exponentially more powerful. —Cade Metz, New York Times, 19 Feb. 2025

The new system possesses 69 superconducting qubits. —IEEE Spectrum, 6 Feb. 2025

Word History

Etymology

qu- (in quantum entry 2) + bit entry 4, probably formed with punning allusion to cubit

Note: According to the American physicist Benjamin Schumacher, in the acknowledgements to a paper ("Quantum coding," Physical Review A, vol. 51, issue 4 [April, 1995], p. 2747), "The term 'qubit' was coined in jest during one of the author's many intriguing and valuable conversations with W. K. Wootters, and became the initial impetus for this work."

First Known Use

1994, in the meaning defined above

Rhymes for qubit

• cubit