  We realize a double-path multimode matter wave interferometer with spinor
Bose-Einstein condensate and observe clear spatial interference fringes as well
as a periodic change of the visibility in the time domain, which we refer to as
the time domain interference and which is different from the traditional
double-path interferometer. By changing the relative phase of the two paths, we
find that the spatial fringes first lose coherence and recover. As the number
of modes increases, the time domain interference signal with the narrower peaks
is observed, which is beneficial to the improvement of the resolution of the
phase measurement. We also investigated the influence of initial phase
configuration and phase evolution rate between different modes in the two
paths. With enhanced resolution, the sensitivity of interferometric
measurements of physical observables can also be improved by properly assigning
measurable quantities to the relative phase between two paths.
