The optical conductivity for a spin-Peierls ground state of (TMTTF)$_{2}$PF$_{6}$ with tetramer formation

Abstract

We theoretically investigate the optical conductivity of (TMTTF) 2 PF 6 in the spin-Peierls ground state within the framework of the exact diagonalization method at absolute zero temperature (T = 0). As an effective model, a 1/4-filled 1D (one-dimensional) extended Hubbard model with tetramerization is employed. Using appropriate parameters of the model which have already been reported, we clarify the electronic photoexcitation energies from the spin-Peierls ground state. Since some experiments indicate the formation of a tetramer in the spin-Peierls ground state of (TMTTF) 2 PF 6 , our results are useful to understand the effects of tetramerization on the optical properties of (TMTTF) 2 PF 6 .