Is there a complex variant of Möbius' function?

There is slight trouble with choice of unit, using ideals instead of Gaussian primes as factors resolves this.

As always the Möbius function encodes the inclusion-exclusion principle.

To invert $$F(\mathfrak n) = (f*1)(\mathfrak n) = \sum_{\mathfrak d|\mathfrak n} f(\mathfrak d)$$ we will use $$\mu(\mathfrak p_1^{r_1} \mathfrak p_2^{r_2} \cdots \mathfrak p_k^{r_k}) = \begin{cases} (-1)^{k} \; \text{ when each $r_i=1$} \\ 0 \; \text{ otherwise}\end{cases}.$$

Then simplifying a bit $$(F*\mu)(\mathfrak p_1^{r_1} \mathfrak p_2^{r_2} \cdots \mathfrak p_k^{r_k}) = \sum_{\epsilon = \{0,1\}^k} (-1)^{\epsilon_1 + \epsilon_2 + \cdots + \epsilon_r} F(\mathfrak p_1^{r_1-\epsilon_1} \mathfrak p_2^{r_2-\epsilon_2} \cdots \mathfrak p_k^{r_k-\epsilon_k}) = f(\mathfrak p_1^{r_1} \mathfrak p_2^{r_2} \cdots \mathfrak p_k^{r_k}).$$

It may be worth checking that we get the same correspondence with Dirichlet series/zeta functions as in the natural numbers case.