I could find from this source -- but also from other works on ZX-calculus -- the following extract:
This looks to me as a generalisation of a 2-qubit Ising gate to an $n$-qubit global Ising gate. Especially considering that the 2-qubit case admits the following synthesis:
I find global gates particularly interesting, hence I am intrigued by the compactness of this representation, both mathematical and graphical.
Is my statement correct, namely, that this representation is a generalised Ising gate?
