WIGNER FUNCTION

The Wigner quasi-probability distribution W(x,p) is the quantum analog of phase space density. Unlike classical probability, it can go negative — a signature of non-classical states.

W(x,p) = (1/πℏ)∫ψ*(x+y)ψ(x-y)e^{2ipy/ℏ}dy

State: Coherent
n (Fock number) 3 α (displacement) 2.0 Squeezing r 0.5 Animation speed 1.0 Toggle animation

Negative values = non-classical
Red = negative · Blue = positive