Quantum Computing Hardware
Which correctly describes the kind of quantum computer called NISQ?
- AA large-scale quantum computer that performs full error correction and runs quantum circuits of any length without errors
- BAn intermediate-scale quantum computer with noise (errors) that does not perform full-scale error correction
- CA device that simulates quantum circuits on a classical computer without using qubits
Show answer and explanation
Answer: B. An intermediate-scale quantum computer with noise (errors) that does not perform full-scale error correction
NISQ stands for Noisy Intermediate-Scale Quantum, a term proposed in 2018 by the physicist John Preskill. Such devices have enough qubits to make simulation on classical computers difficult, but because they do not perform full-scale error correction, the depth of circuit they can run is limited by the gate error rates. For NISQ devices, researchers are studying error mitigation, which estimates the effect of errors and reduces it in post-processing, and methods that combine quantum and classical computation. Large-scale machines that perform error correction are distinguished as fault-tolerant quantum computers (FTQC).
- A. This describes a fault-tolerant quantum computer (FTQC).
- B. Correct. It refers to intermediate-scale devices that are noisy and do not perform full-scale error correction.
- C. NISQ refers to devices that use real qubits.