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

A number of companies are experimenting with hardware qubit designs that can flag when one type of common error occurs, and there has been progress with developing logical qubits that enable error correction. —John Timmer, Ars Technica, 27 Sep. 2024

But developers still are struggling to build dependable and scalable basic infrastructure, such as quantum bits, or qubits. —Robert McCoppin, Chicago Tribune, 21 Oct. 2024

However, such machines would require thousands or even millions of qubits with low error rates—a technological milestone that is still years, if not decades, away. —Craig S. Smith, Forbes, 16 Oct. 2024

But Goswami and co say even the best quantum algorithms require a large number of qubits. —The Physics Arxiv Blog, Discover Magazine, 30 July 2024

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