Analytic approach to the one-dimensional spin-Peierls system in the entirefrequency range

We use the two cutoff renormalization group (RG) method to study the spin-P eierls model in one dimension for the entire phonon frequency range. We int egrate out the phonon and solve the effective Fermion system via mean field and RG methods. We make use of the symmetry that the Neel, dimerization, a nd spin current order parameters form an SU(2) triplet based on resolving t he fermion into left and right movers. We present the phase diagram and dis cuss its implications for the organic charge-transfer salt (TMTTF)(2)PF6.