1.8 - QPU Gate Equivalence

The lecture slides are available here Download here.

In many cases, a certain quantum computer doesn't implement certain quantum gates. In this case, it is useful to use quantum equivalence to express the transformation of the missing gate. In this lecture, I discuss briefly quantum gate equivalences. A PHASE(180) operation can be combined with two HADs to produce the exact equivalent of a NOT operation. A PHASE(180) instruction can also be realized from HAD and NOT operations. Combining instructions also lets us produce interesting new operations that do not exist at all in the world of conventional logic. The ROOT-of-NOT operation (RNOT) is one such example. It’s quite literally the square root of the NOT operation: when applied twice, it performs a single NOT.