Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 30: Superconductivity: Fe-based Superconductors - Theory

TT 30.7: Vortrag

Dienstag, 8. März 2016, 12:45–13:00, H19

Spin-wave Excitations in Tetragonal and Orthorhombic Spin-Density-Wave Phases of Iron Pnictides — •Daniel David Scherer and Brian Møller Andersen — Niels Bohr Institute, University of Copenhagen, 2100, Copenhagen, Denmark

The most prominent and abundant spin-density-wave (SDW) state found theoretically and experimentally in the Fe-based superconductor materials features stripy orthorhombic magnetic order in the Fe layer with ordering vectors Q₁=(π,0) or Q₂=(0,π). Recently, however, tetragonal magnetic orders have been discovered in these systems [1-4]. A candidate for a commensurate tetragonal SDW state is a spin- and charge-ordered state (SCO) that was previously understood [5,6] as a superposition of two stripy orders with an induced checkerboard charge order. Starting from a DFT-derived 5-orbital model for the electronic degrees of freedom, we here focus on a theoretical investigation of the spin-wave spectra in the orthorhombic stripy SDW and tetragonal SCO states within an itinerant weak-coupling approach, and present a comprehensive comparison of our results to experimental data.

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