  The geometry of submanifolds is intimately related to the theory of functions
and vector bundles. It has been of fundamental importance to find out how those
two objects interact in many geometric and physical problems. A typical example
of this relation is that the Picard group of line bundles on an algebraic
manifold is isomorphic to the group of divisors, which is generated by
holomorphic hypersurfaces modulo linear equivalence. A similar correspondence
can be made between the K-group of sheaves and the Chow ring of holomorphic
cycles. There are two more very recent examples of such a relation. The mirror
symmetry in string theory has revealed a deeper phenomenon involving special
Lagrangian cycles (cf. [SYZ]). On the other hand, C. Taubes has shown that the
Seiberg-Witten invariant coincides with the Gromov-Witten invariant on any
symplectic 4-manifolds.
  In this paper, we will show another natural interaction between Yang-Mills
connections, which are critical points of a Yang-Mills action associated to a
vector bundle, and minimal submanifolds, which have been studied extensively
for years in classical differential geometry and the calculus of variations.
