Kink Structure in the Quasiparticle Band of Doped Hubbard Systems
arXiv:cond-mat/0507564 · doi:10.1143/JPSJ.74.2397
Abstract
By making use of the self-consistent projection operator method with high-momentum and high-energy resolutions, we find a kink structure in the quasiparticle excitation spectrum of the two-dimensional Hubbard model in the underdoped regime. The kink is caused by a mixing between the quasiparticle state and excitations with short-range antiferromagnetic order. We suggest that this might be the origin of the strong concentration dependence of the 'kink' found in La_{2-x}Sr_{x}CuO_{4} (x=0.03-0.07).
3 pages, 4 figures. to be published in J. Phys. Soc. Jpn., Vol. 74, No. 9, September 15, 2005