# What quantum gate is XNOR equivalent to?

The standard way to implement a reversible XOR gate is by means of a controlled-NOT gate or CNOT; this is the "standard quantum XOR operation". Physics.Stackexchange

Is there a "standard quantum XNOR operation"?

The XNOR gate (sometimes ENOR, EXNOR or NXOR and pronounced as Exclusive NOR) is a digital logic gate whose function is the logical complement of the exclusive OR (XOR) gate. Wikipedia

Alternatively, what is the logical complement of the CNOT gate?

• $\text{cNOT}\cdot(\mathbb{1}\otimes X)$? What would the circuit look like (not sure which qubit would get the x)? Also, would it be accurate to call this 'gate' not CNOT? – meowzz Oct 1 '18 at 1:22