Disorder effects in ARPES spectral functions

The interplay of disorder and interactions are known to cause novel effects in complex oxides such as cuprates and manganites. Understanding the single-particle spectral function, with a goal of separating out the effects of disorder and interactions, is an important step in elucidating the physics of these complex materials. We numerically evaluate the spectral function $A({\bf r},{\bf r}';\omega)$ for model Hamiltonians with disorder. ARPES measures the occupied part of $A$, averaged over the center-of-mass variable $({\bf r}+{\bf r}')/2$ and Fourier transformed in $({\bf r}-{\bf r}')\to {\bf k}$. We analyze the line shape of the energy distribution curves (EDC) and momentum distribution curves (MDC). We compare our results with experiments on manganites, and on intentionally disordered chalcogenides.