quantum computer

American  

noun

1. a computer that makes use of the quantum states of electrons or other particles to store and process information as quantum bits.

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quantum computer British  

noun

1. a type of computer which uses the ability of quantum systems to be in many different states at once, thus allowing it to perform many different computations simultaneously

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quantum computer Scientific  

1. A computer that exploits the quantum mechanical properties of superposition in order to allow a single operation to act on a large number of pieces of data. In a quantum computer, the data to be manipulated, represented in quantum bits, exists in all possible states simultaneously, in superposition. This allows a single operation to operate over all of these states at once, in contrast with a classical computer, which must carry out an operation for each state separately. Because of the difficulty of creating environments small enough for quantum effects to emerge but sufficiently isolated to prevent interaction with outside influences such as heat, only extremely rudimentary quantum computers currently exist, though algorithms for possible future devices are being developed.

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Other Word Forms

• quantum computing noun

Etymology

Origin of quantum computer

First recorded in 1980–85

Example Sentences

In fact, its companies represent between them the full range of qubit types – all the routes physicists are hoping will lead to the first reliable and ultra-powerful quantum computer.

From BBC • Apr. 13, 2026

When a quantum computer is used to calculate properties such as the energy or the state of a qubit, the result is largely determined by the final layers.

From Science Daily • Apr. 6, 2026

Google’s researchers said a quantum computer may be on the horizon that’s powerful enough to crack a bitcoin wallet’s secret key in as few as nine minutes, potentially giving attackers access to investors’ funds.

From MarketWatch • Mar. 31, 2026

“We’ve been very, very vocal on our aim to build a large-scale quantum computer by 2029 or 2030,” Weedbrook said.

From Barron's • Mar. 30, 2026

A quantum computer uses qubits—shorthand for quantum bits—to harness the behavior of subatomic particles, which can exist in multiple states at once.

From The Wall Street Journal • Mar. 23, 2026