Quantum information

• How Are Qubits Created and Entangled?
  Qubits are encoded in controllable physical systems, then entangled by interactions or gates; a Hadamard and CNOT give a standard example.
• Can a Local Operation Disentangle Two Parties?
  A local unitary cannot change bipartite entanglement, but a local measurement or noisy channel can destroy it. See the Bell-pair proof.