Superposition
Definition
In quantum mechanics, superposition is a fundamental principle which holds that a physical system—such as an electron—exists partly in all its particular, theoretically possible states simultaneously; but when measured, it gives a result corresponding to only one of the possible configurations.
Why It Matters
Superposition is one of the key properties that makes quantum computing possible. It allows a qubit to represent both a 0 and a 1 at the same time, enabling a massive amount of parallel computation.
Contextual Example
Imagine a spinning coin. While it is spinning, it is neither heads nor tails, but a combination of both. This is analogous to a qubit in superposition. Only when the coin lands (when the qubit is measured) does it settle into a single, definite state (heads or tails, 0 or 1).
Common Misunderstandings
- Superposition is a core concept of quantum mechanics and is deeply counter-intuitive compared to our everyday classical world.
- It is what allows a quantum computer with N qubits to represent 2^N states simultaneously.