  A Hilbert space metric is found for the SU(2|1)-invariant `superflag' Landau
models, parametrized by integer 2N' and real number M, such that the Hilbert
space norm is positive definite. The spectrum of these unitary super-Landau
models is determined. The M=0 case yields a unitary Landau model on the
supersphere SU(2|1)/U(1|1) with U(1) charge 2N=2N'+1. For the generic unitary
superflag model, the manifest SU(2|1) symmetry is dynamically enhanced to
SU(2|2); this is the `spherical' analog of the hidden worldline supersymmetry
found previously in the planar limit.
