Perfect State Transfer in Arbitrary Distance

Abstract: Quantum Perfect State Transfer (PST) is a fundamental tool of quantum communication in a network. It is considered a rare phenomenon. The original idea of PST depends on the fundamentals of the continuous-time quantum walk. A path graph with at most three vertices allows PST. Based on the Markovian quantum walk, we introduce a significantly powerful method for PST in this article. We establish PST between the extreme vertices of a path graph of arbitrary length. Moreover, any pair of vertices $j$ and $n - j - 1$ in a path graph with $n$ vertices allow PST for $0 \leq j < \frac{n - 1}{2}$. Also, no cycle graph with more than $4$ vertices does not allow PST based on the continuous-time quantum walk. In contrast, we establish PSTs based on Markovian quantum walk between the pair of vertices $j$ and $j + m$ for $j = 0, 1, \dots (m - 1)$ in a cycle graph with $2m$ vertices.