  Multipath holographic interference in strong-field quantum tunnel ionization
is key to revealing sub-Angstrom attosecond dynamics for molecular movies. This
critical sub-cycle motion is often obscured by longer time-scale effects such
as ring-shaped patterns that appear in above-threshold ionization (ATI). In the
present work, we overcome this problem by combining two novel techniques in
theory and experimental analysis: unit-cell averaging and time-filtering data
and simulations. Together these suppress ATI rings and enable an unprecedented
highly-detailed quantitative match between strong-field ionization experiments
in argon and the Coulomb-quantum orbit strong-field approximation (CQSFA)
theory. Velocity map images reveal fine modulations on the holographic
spider-like interference fringes that form near the polarization axis. CQSFA
theory traces this to the interference of three types of electron pathways. The
level of agreement between experiment and theory allows sensitive determination
of quantum phase differences and symmetries, providing an important tool for
quantitative dynamical imaging in quantum systems.
