quantum entanglement means: measuring one qubit instantly determines the other's state

Quantum superposition

A qubit exists in superposition of |0⟩ and |1⟩

Quantum logic gate

Hadamard gate puts a qubit into equal superposition of |0⟩ and |1⟩

Quantum computing

Quantum computers can solve certain problems exponentially faster than classical computers

Entropy H = -Σ p(x) log₂ p(x) measures average surprise in bits

Entropy H = -Σ p(x) log₂ p(x) quantifies uncertainty in a system

the union bound says: P(A∪B) ≤ P(A) + P(B)

The union bound states: P(A∪B) ≤ P(A) + P(B)

Measurement in quantum mechanics

Quantum states describe probabilities, not certainties