Abstract
We present an angle resolved photoemission study of , a prototype system for the observation of Mott transitions in correlated materials. We show that the spectral features corresponding to the quasiparticle peak in the metallic phase present a marked wave vector dependence, with a stronger intensity along the direction. The analysis of their intensity for different probing depths shows the existence of a characteristic length scale for the attenuation of coherent electronic excitations at the surface. This length scale, which is larger than the thickness of the surface region as normally defined for noncorrelated electronic states, is found to increase when approaching the Mott transition. These results are in agreement with the behavior of quasiparticles at surfaces as predicted by Borghi et al. [Phys. Rev. Lett. 102, 066806 (2009)].
- Received 3 October 2008
DOI:https://doi.org/10.1103/PhysRevLett.102.066805
©2009 American Physical Society
Synopsis
Insulating behavior is only skin deep
Published 17 February 2009
A new analysis of photoemission measurements on a material undergoing a metal-insulator transition suggests that an apparent surface “dead layer” is really a bulk effect.
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