Grand unification of all discrete Wigner functions on d × d phase space
Lucky K. Antonopoulos, Dominic G. Lewis, J. Davis, Nicholas Funai, Nicolas C. Menicucci · Physical Review A · 2025
Wigner functions help visualize quantum states and dynamics while supporting quantitative analysis in quantum information. In the discrete setting, many inequivalent constructions coexist for each Hilbert-space dimension. This fragmentation obscures which features are fundamental and which are artifacts of representation. We introduce a stencil-based framework that exhausts all possible $d\ifmmode\times\else\texttimes\fi{}d$ discrete Wigner functions for a single $d$-dimensional quantum system (including a novel one for even $d$), subsuming known forms. We also give explicit invertible linear maps between definitions within the same $d$, enabling direct comparison of operational properties and exposing representation dependence.