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

Doing more sophisticated calculations may mean thousands of logical qubits. —John Timmer, Ars Technica, 9 July 2024

And a qubit without spin can maintain its quantum state for a longer period of time. —IEEE Spectrum, 15 June 2024

For certain types of problems, potential solutions can be thought of as quantum waves sloshing among the qubits. —science.org, 10 June 2024

Charlie, however, always measures the qubit with the same basis. —Anil Ananthaswamy, Scientific American, 25 June 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