A class of gcd-graphs having Perfect State Transfer

Abstract

Let $G$ be a graph with adjacency matrix $A$. The transition matrix corresponding to $G$ is defined by $H(t):=\exp \left(itA\right)$, $t\in\Rl$. The graph $G$ is said to have perfect state transfer (PST) from a vertex $u$ to another vertex $v$, if there exist $τ\in\Rl$ such that the $uv$-th entry of $H(\tau )$ has unit modulus. The graph $G$ is said to be periodic at $τ\in\Rl$ if there exist $γ\in\Cl$ with $|\gamma |=1$ such that $H(\tau )=\gamma I$, where $I$ is the identity matrix. A $gcd$-graph is a Cayley graph over a finite abelian group defined by greatest common divisors. In this paper, we construct classes of $gcd$-graphs having periodicity and perfect state transfer.