7. Multi-Qubit: Entanglement

Entanglement

Entanglement occurs when a multi-qubit state cannot be written as a tensor product of individual qubit states.

Imagine you have two dice. You throw one in New York and one in Tokyo. If they are entangled, every time the New York die lands on 6, the Tokyo die instantly lands on 6.

Interactive Task: Create a Bell Pair. Use an H gate on q0, then a CNOT gate (control q0, target q1). Measure both. They will always match!