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arXiv · 1505.00753

Tetragonal and collapsed-tetragonal phases of CaFe2As2 -- a view from angle-resolved photoemission and dynamical mean field theory

Ambroise van Roekeghem·Pierre Richard·Xun Shi·Shangfei Wu·Lingkun Zeng·Bayrammurad Saparov·Yoshiyuki Ohtsubo·Tian Qian·Athena S. Sefat·Silke Biermann·Hong Ding
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Abstract

We present a study of the tetragonal to collapsed-tetragonal transition of CaFe2As2 using angle-resolved photoemission experiments and dynamical mean field theory-based electronic structure calculations. We observe that the collapsed-tetragonal phase exhibits reduced correlations and a higher coherence temperature due to the stronger Fe-As hybridization. Furthermore, a comparison of measured photoemission spectra and theoretical spectral functions shows that momentum-dependent corrections to the density functional band structure are essential for the description of low-energy quasiparticle dispersions. We introduce those using the recently proposed combined "Screened Exchange + Dynamical Mean Field Theory" scheme.

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Ambroise van Roekeghem, Pierre Richard, Xun Shi, Shangfei Wu, Lingkun Zeng, Bayrammurad Saparov, Yoshiyuki Ohtsubo, Tian Qian, Athena S. Sefat, Silke Biermann, Hong Ding. 2015-05-04. Tetragonal and collapsed-tetragonal phases of CaFe2As2 -- a view from angle-resolved photoemission and dynamical mean field theory. https://doi.org/10.1103/physrevb.93.245139

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