  We construct a coupled quantum vortex superposition state (CVSS), since in
actual physical systems, linear Schrodinger equations will not be available
because of a nonlinear effect. By studying the dynamic evolution of CVSS both
analytically and numerically, we show that the superposition of vortex states
is not only a mathematical algebraic sum, but also corresponds to a physical
process of formation. Moreover, a new method to generate quantum vortex lattice
in CVSS research is given. By comparing with the density profiles and phase
distributions of quantum vortex state, we have a new understanding of vortex
state, which means that there is spatial degeneracy of angular momentum of a
particle. According to this idea, a free particle can be understood as the
center of mass of a ring-shaped matter in space. Thus, we revisit the
double-slit interference experiment and give a new interpretation.
