Abstract
Using angle-resolved photoemission spectroscopy, we study the evolution of the number of carriers in as a function of Co content and temperature. We show that there is a -dependent energy shift compared to density functional calculations, which is large below 100 K at low Co contents and reduces the volume of hole and electron pockets by a factor 2. This shift becomes negligible at high Co content and could be due to interband charge or spin fluctuations. We further reveal that the bands shift with temperature, changing significantly the number of carriers they contain (up to 50%). We explain this evolution by thermal excitations of carriers among the narrow bands, possibly combined with a temperature evolution of the -dependent fluctuations.
- Received 29 January 2013
DOI:https://doi.org/10.1103/PhysRevLett.110.167002
© 2013 American Physical Society