Non-adiabatic approach to optical conductivity in the one-dimensional half-filled Holstein model

作者：Wang, Q^*; Zheng, H

来源：Physics Letters A, 2003, 314(4): 304-314.

DOI：10.1016/S0375-9601(03)00857-0

• non-adiabatic effect
• electron-phonon interaction
• optical conductivity

The optical conductivity in the one-dimensional half-filled Holstein model of spin-1/2 electrons is investigated by developing an analytical non-adiabatic approach based on the unitary transformation method. The non-adiabatic effects due to finite phonon frequency omega(0) > 0 are treated through an energy-dependent electron-phonon scattering function delta(k', k) and the Green's function method is used to implement the perturbation treatment. The calculated optical conductivity and the density of states of electrons do not have the inverse-square-root singularity but have a peak above, the gap edge and there exists,a significant tail below the peak. This indicates that due to the non-adiabatic effects the Peierls gap shifts and the optical excitation spectrum does not peak at the correspondingly renormalized gap edge.

• 出版日期2003-8-4
• 单位上海交通大学