Determining the Surface-To-Bulk Progression in the Normal-State   Electronic Structure of Sr2RuO4 by Angle-Resolved Photoemission and Density   Functional Theory
  In search of the potential realization of novel normal-state phases on the surface of Sr2RuO4 - those stemming from either topological bulk properties or the interplay between spin-orbit coupling (SO) and the broken symmetry of the surface - we revisit the electronic structure of the top-most layers by ARPES with improved data quality as well as ab-initio LDA slab calculations. We find that the current model of a single surface layer (\surd2x\surd2)R45{\deg} reconstruction does not explain all detected features. The observed depth-dependent signal degradation, together with the close quantitative agreement with LDA+SO slab calculations based on the LEED-determined surface crystal structure, reveal that (at a minimum) the sub-surface layer also undergoes a similar although weaker reconstruction. This points to a surface-to-bulk progression of the electronic states driven by structural instabilities, with no evidence for Dirac and Rashba-type states or surface magnetism. 
C.N. Veenstra, Z.-H. Zhu, B. Ludbrook, M. Capsoni, G. Levy, A.   Nicolaou, J. A. Rosen, R. Comin, S. Kittaka, Y. Maeno, I. S...
cond-mat.str-el cond-mat.supr-con