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

That trick bumped the qubit creation yield above 85 percent for predictable, high-density manufacturing. — Mrigakshi Dixit, Interesting Engineering, 21 July 2026

While this process is acceptable for producing a few qubits in a laboratory environment, it can’t be used to build a million-qubit processor. — Paul Smith-Goodson, Forbes.com, 21 July 2026

Because of superposition, a qubit can be zero, one or a mix of both at once. — Aldo Romero, The Conversation, 15 July 2026

And that can be done in parallel with the error detection and correction system that manages the logical qubit. — John Timmer, ArsTechnica, 10 July 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