  Higher-dimensional models of neutrino physics with one or more right-handed
neutrinos in the bulk have attracted considerable attention in recent years.
However, a critical issue for such models is to find a way of introducing the
required flavor dependence needed for generating neutrino oscillations. In this
paper, we point out that a natural ``minimal'' framework that accomplishes this
can be constructed by combining the bulk-neutrino hypothesis for right-handed
neutrinos with the split-fermion scenario for left-handed neutrinos. This
combination leads to a unique flavor signature for neutrino phenomenology which
easily incorporates large flavor mixing angles. This hybrid scenario also has a
number of additional important features. For example, one previous difficulty
of the split-fermion scenario applied to neutrinos has been that the mass
matrix is exponentially sensitive to neutrino displacements within the brane.
However, in our hybrid scenario, the interactions between the brane and bulk
naturally convert this dependence from exponential to linear. Another important
feature is that our hybrid scenario provides its own natural regulator for
Kaluza-Klein sums. Thus, in our scenario, all Kaluza-Klein summations are
manifestly finite, even in cases with multiple extra dimensions. But most
importantly, our mechanism completely decouples the effective neutrino flavor
mixing angles from the sizes of the overlaps between the neutrino wavefunctions
within the brane. Thus, we are able to obtain large neutrino mixing angles even
when these neutrinos have significant spatial separations and their overlaps
vanish.
