When finding the poles of something like the following transfer function, would I be able to write $z=\sqrt[L]{\mu}$ since square roots aren't technically defined on the complex plane?
$$Y(z) = \frac{a_L z^L + a_{L-1}z^{L-1} + ... +a_0}{z^L - \mu}$$
where $a_j,\mu \in\mathbb{C}$, $|\mu|<1$ and L is positive.