qubit

noun

qu·​bit ˈkyü-bət How to pronounce qubit (audio)
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Companies like Google, Microsoft, Amazon and IBM are aggressively pursuing gate-model quantum computing, each with different qubit technologies and strategies. Rachel Curry, CNBC, 6 Apr. 2025 These are thorough descriptions, and in the case of qubits, the possibilities grow exponentially. Quanta Magazine, 28 Mar. 2025 Since then, quantum computing computers have been built with thousands of qubits and firms that build and operate such systems have gone public. Peter Cohan, Forbes, 23 Mar. 2025 So, the key measurement done here is comparing a chain that has three cat qubits and two transmons to one that has five cat qubits and four transmons. John Timmer, Ars Technica, 26 Feb. 2025 See All Example Sentences for qubit

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

Time Traveler
The first known use of qubit was in 1994

Browse Nearby Words

Cite this Entry

“Qubit.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/qubit. Accessed 24 Apr. 2025.

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!