Doping Evolution of the Underlying Fermi Surface in La2-xSrxCuO4

Abstract

We have performed a systematic doping dependent study of La${}_{2-x}$Sr${}_x$CuO${}_4$ (LSCO) (0.03$\le x\le$0.3) by angle-resolved photoemission spectroscopy. In the entire doping range, the underlying ``Fermi surface" determined from the low energy spectral weight approximately satisfies Luttinger's theorem, even down to the lightly-doped region. This is in strong contrast to the result on Ca${}_{2-x}$Na${}_x$CuO${}_2$Cl${}_2$ (Na-CCOC), which shows a strong deviation from Luttinger's theorem. The differences between LSCO and Na-CCOC are correlated with the different behaviors of the chemical potential shift and spectral weight transfer induced by hole doping.

4 pages, 4 figures