However, quantum information cannot be cloned or copied due to the no-cloning theorem (which states that it is impossible to create an independent and identical copy of an arbitrary unknown quantum state).
Classical error correction relies on redundancy, i.e., repetition. However, quantum information cannot be cloned or copied due to the no-cloning theorem (which states that it is impossible to create an independent and identical copy of an arbitrary unknown quantum state). Therefore, a new error correction method is required for quantum computing systems.