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

Some companies still need 1,000 physical qubits to correct errors and eliminate the noise generated by one underlying logical qubit. —Jim Edwards, Fortune, 17 Feb. 2026

These studies confirmed that quantum bits (qubits) could be transmitted over long-distance fiber optic infrastructure. —Aman Tripathi, Interesting Engineering, 5 Feb. 2026

Furthermore, neutral atoms are highly mobile, facilitating the dynamic rearrangement of qubits for efficient algorithms and new error correction techniques. —Gil Press, Forbes.com, 27 Jan. 2026

The practical potential Mark Hillery, a professor of physics at City University of New York who specializes in quantum information, questions whether the approach truly counts as cloning, as only one qubit ends up in the same state as the initial qubit, and no additional copies are produced. —IEEE Spectrum, 25 Jan. 2026

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 acknowledgments 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