  We propose a real-space renormalization group approach for evaluating
persistent current in a multi-channel quasiperiodic fibonacci tight-binding
ring based on a Green's function formalism. Unlike the traditional methods, the
present scheme provides a powerful tool for the theoretical description of
persistent current with a very high degree of accuracy in large periodic and
quasiperiodic rings, even in the micron scale range, which emphasizes the merit
of this work.
