  Spatial quantum enhancement effects are studied under a unified framework. It
is shown that the multiphoton absorption rate of photons with a
quantum-enhanced lithographic resolution is reduced, not enhanced, contrary to
popular belief. The use of adiabatic soliton expansion is proposed to beat the
standard quantum limit on the optical beam displacement accuracy, as well as to
engineer an arbitrary multiphoton interference pattern for quantum lithography.
The proposed scheme provides a conceptually simple method that works for an
arbitrary number of photons.
