What is the fundamental problem quantum error correction (QEC) aims to solve?

QEC aims to solve the problem of decoherence and gate errors in quantum computers. Unlike classical bits, quantum bits (qubits) are extremely fragile and susceptible to environmental noise, leading to errors that corrupt quantum information. QEC seeks to protect this information by encoding it in a redundant manner, allowing for the detection and correction of these errors without collapsing the quantum state.