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

Quantum computers tap into the principles of superposition and entanglement, processes which allow quantum bits (qubits) to process enormous amounts of data simultaneously, enabling faster solutions to complex computational problems in finance. —Roman Reznikov, Forbes.com, 6 Aug. 2025

Building quantum computers requires chips made up of qubits, which are the basic units of quantum information. —Karoline Leonard, Austin American Statesman, 30 July 2025

Quantum computers made of antimatter qubits are still a long way off and would be much harder to build than matter quantum computers—which are already extremely tricky. —Clara Moskowitz, Scientific American, 28 July 2025

Quantum one-way state generators would instead generate locks made of units of quantum information called qubits. —Ben Brubaker, Quanta Magazine, 25 July 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