The current state of quantum computing[1] is referred to as the noisy intermediate-scale quantum (NISQ) era,[2][3] characterized by quantum processors containing up to 1,000 qubits which are not advanced enough yet for fault-tolerance or large enough to achieve quantum advantage.[4][5] These processors, which are sensitive to their environment (noisy) and prone to quantum decoherence, are not yet capable of continuous quantum error correction. This intermediate-scale is defined by the quantum volume, which is based on the moderate number of qubits and gate fidelity. The term NISQ was coined by John Preskill in 2018.[6][2]
According to Microsoft Azure Quantum scheme, NISQ computation is considered level 1, the lowest of the quantum computing implementation levels.[7][8]
In October 2023, the 1,000 qubit mark was passed for the first time by Atom Computing's 1,180 qubit quantum processor.[9] However, as of 2024, only two quantum processors have over 1,000 qubits, with sub-1,000 quantum processors still remaining the norm.[10]