Quantum computing – A modern computing that uses quantum physics to process information.
A normal computer stores information as bits, which are either 0 or 1. A quantum computer uses qubits, which can behave like 0, 1, or superposition of 0 and 1 of both. This property is called superposition.
Three ideas are especially important:
Superposition: A qubit can represent a combination of 0 and 1 until it is measured.
Mathematically superposition is represented as – |ψ⟩ = α|0⟩ + β|1⟩, where ∣α∣2+∣β∣2=1 and α, β are probability amplitudes. This means a qubit can be 50% chance it can be in 0 state, or 50% chance it can be in 1 state. It is not always 50% , 50% , it can be 90% in 0 state,10% in 1 state, ultimately ∣α∣2+∣β∣2=1 that is total probability is 100%
understand the notations used in above equation
- |ψ⟩ – Ket Psi
- |0⟩ – Ket 0
- |1⟩ – Ket 1
Thats how they are pronounced, a mathematical notation to represent superposition
Entanglement: 2 Qubits can become strongly correlated, so their quantum states have to be described together. What does it mean ? if one qubit change its state, it impact other qubit instantly
Interference: Quantum algorithms manipulate probability amplitudes so that useful outcomes become more likely and unwanted ones can cancel out.