Bad Qubits — Learn Quantum by Doing

True / False

Claim: The no-cloning theorem follows from the linearity/unitarity of quantum mechanics and implies that a single unitary can clone two states

|\psi\rangle

and

|\phi\rangle

only if their overlap

\langle\psi|\phi\rangle

is 0 or 1; consequently it forbids cloning a non-orthogonal pair such as

|0\rangle

and

|+\rangle

, whose overlap is

1/\sqrt{2}