However, with error suppression and mitigation, quantum computing still allows for processing at a level that cannot be easily accomplished even on the largest classical supercomputers.
Quantum computing also faces two major challenges – accuracy and scaling. Errors are introduced through both the stability (or lack thereof) of qubits and potential interference from other qubits. Maintaining stability or lifespan of a qubit in a superposition state is challenging and may be limited to a few milliseconds or microseconds. Additionally, qubits can interfere with neighboring qubits. As a result, error suppression, correction, and mitigation techniques are being developed to work both individually and together to increase computation accuracy. Error suppression does front-end processing based on the knowledge of the system and circuits to offset potential errors, such as making alterations to the pulses that control the qubits. Error mitigation corrects errors in postprocessing based on a noise model. Error correction, on the other hand, requires many additional qubits, to correct errors during execution. While error correction may be the most effective way to eliminate errors, it comes at a significant cost. However, with error suppression and mitigation, quantum computing still allows for processing at a level that cannot be easily accomplished even on the largest classical supercomputers.