Graphs of Unitary Matrices

Abstract

The support of a matrix $M$ is the $(0,1)$-matrix with $ij$-th entry equal to $1$ if the $ij$-th entry of $M$ is non-zero, and equal to $0$, otherwise. The digraph whose adjacency matrix is the support of $M$ is said to be the digraph of $M$. In this paper, we observe some general properties of digraphs of unitary matrices.