Quantum superposition is a fundamental concept in quantum mechanics, stemming from the linearity of the Schrödinger equation. This principle allows solutions to be expressed as superpositions of eigenfunctions, ensuring that such combinations are also valid solutions.
In quantum computing, qubits serve as the analog of classical bits and can exist in a superposition state. Unlike classical bits, which represent information sequentially, qubits maintain multiple states simultaneously. However, controlling these superpositions is a significant challenge, particularly for systems like nuclear spins with weak coupling. While this strength contributes to their robustness against disturbances, it complicates the process of reading out results accurately.