Swap test
= Swap test
{wiki}
The swap test on pure states $|a\rangle,|b\rangle$ returns ancilla zero with probability
$$
p_0=\frac12\left(1+|\langle a|b\rangle|^2\right).
$$
= Swap test
{wiki}
The swap test on pure states $|a\rangle,|b\rangle$ returns ancilla zero with probability
$$
p_0=\frac12\left(1+|\langle a|b\rangle|^2\right).
$$