On the Abel-Jacobi Map for Divisors of Higher Rank on a Curve
  The aim of this paper is to present an algebro-geometric approach to the study of the geometry of the moduli space of stable bundles on a smooth projective curve defined over an algebraically closed field $k$, of arbitrary characteristic. This establishes a bridge between the arithmetic approach of Harder, Narasimhan et al. and the gauge group approach of Atiyah and Bott. One of the basic ideas is to consider a notion of divisor of higher rank and a suitable Abel-Jacobi map generalizing the classical notions in rank one. 
Emili Bifet, Franco Ghione and Maurizio Letizia