We compute the Frobenius complexity for the determinantal ring of prime characteristic $p$ obtained by modding out the $2 \times 2$ minors of an $m \times n$ matrix of indeterminates, where $m > n \ge 2$. We also show that, as $p \to \infty$, the Frobenius complexity approaches $m-1$.

18 pages, comments welcome; new material added regarding the limit of Frobenius complexity as p goes to infinity and connections to the Perron-Frobenius theorem. arXiv admin note: text overlap with arXiv:1401.0234