We investigate the effects of a finite chemical potential μ in QCD viewed
as a disordered medium. In the quenched approximation, A4=iμ induces a
complex electric Aharonov-Bohm effect that causes the diagonal contribution to
the quark return probability to vanish at μ=mπ/2 (half the pion mass).
In two-color QCD, the weak-localization contribution to the quark return
probability remains unaffected causing a mutation in the spectral statistics.
In full QCD, the complex electric flux is screened and the light quarks are
shown to diffuse asymmetrically with a substantial decrease in the conductivity
along the `spatial' directions. Mean-field arguments suggest that a d=1
percolation transition may take place in the range 1.5ρ0<ρ<3ρ0,
where ρ0 is nuclear matter density.Comment: 4 page