Charge Stripes and Electronic States in Underdoped La2-x Sr x CuO4

Abstract

We investigate the electronic states of underdoped La2-x Sr x CuO4 (LSCO) by the t-tʼ-t”- J V model containing charge stripes. The numerically exact diagonalization calculation is employed on small clusters. The model with vertical stripes consistently explains the physical properties observed in the angle-resolved photoemission and the optical conductivity experiments near x=0.12, while the diagonal-stripe model does not explain them. Rather the latter seems to be applicable to the insulating phase where the presence of diagonal stripes is experimentally observed. These results demonstrate a crucial role of the charge stripes in LSCO.