Electronic Structure of the NaxCoO2 Surface

The idea that surface effects may play an important role in suppressing e(g)(') Fermi surface pockets on NaxCoO2 (0.333 <= x <= 0.75) has been frequently proposed to explain the discrepancy between local-density approximation calculations which find e(g)(') hole pockets present and Angle resolved photoemission spectra (ARPES) experiments, which do not observe the hole pockets. Since ARPES is a surface sensitive technique, it is important to investigate the effects that surface formation will have on the electronic structure. We show that a combination of surface formation and contamination effects could resolve the ongoing controversy between ARPES experiments and theory.