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

Unlike traditional computers that use binary bits (limited to values of either 0 or 1), quantum computers utilize qubits that can exist in multiple states simultaneously. —Trefis Team, Forbes, 14 Mar. 2025

These can solve a wide range of algorithms, but have been limited by the frequency of errors in their qubits. —Ashley Belanger, Ars Technica, 12 Mar. 2025

Amazon's design simplifies error correction and requires only 1/10th as many qubits per bit of information. —New Atlas, 28 Feb. 2025

Building a system boasting a million qubits will take collaborations with world-leading semiconductor manufacturers, according to Barrett. —Jordan Novet, CNBC, 27 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