Perron number of a cyclotomic graph

We define Cyclotomic matrix and Cyclotomic graph. For A an integer symmetric matrix, all roots of A(x) are real algebraic integers and RA(z) is cyclotomic if A has spectral radius at most 2. If the Mahler measure of A is 1, then A is a cyclotomic matrix. We find the Perron number of the graphs whose adjacency matrices are the symmetric matrices having all its entries from the set {0, 1} and only zeros on the diagonal.