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Strong fluctuations and itinerant magnetic frustration in a multiorbital model for SrCo2As2

ORAL

Abstract

Despite the observation of strong stripe antiferromagnetic fluctuations, the paradigmatic cobalt pnictide metallic magnet SrCo2As2 exhibits an intriguing lack of magnetic order. Minute amounts of substitutions of Co by Ni, corresponding to electron doping, however, induce long-range spiral magnetic order in the metallic magnet. To understand these puzzling observations, we investigate a realistic interacting multi-orbital model for SrCo2As2 that takes both Co d-orbitals and As p-orbitals into account. We find that the static paramagnetic RPA spin susceptibility exhibits a crossover from dominantly ferromagnetic to dominantly stripe antiferromagnetic fluctuations as a function of both doping and modifications of Hubbard to Hund interactions. In agreement with experimental observations, our model shows a clear tendency towards the development of magnetic order under electron doping, while hole doping moves the system further into the paramagnetic regime. By analyzing the orbital character of the leading magnetic fluctuations, our study elucidates the proposed mechanism of itinerant magnetic frustration as the origin of the observed lack of magnetic order.

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Presenters

  • Ana-Marija Nedic

    Iowa State University

Authors

  • Ana-Marija Nedic

    Iowa State University

  • Morten Holm Christensen

    School of Physics and Astronomy, University of Minnesota, University of Minnesota

  • Yongbin Lee

    Ames Laboratory, Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, USA, Iowa State University

  • Rafael Fernandes

    University of Minnesota, School of Physics and Astronomy, University of Minnesota, Physics, University of Minnesota, School of Physics and Astronomy, University of Minnesota, Minneapolis, 55455 MN, School of Physics and Astronomy, University of Minnesota, Minneapolis

  • Robert J McQueeney

    Ames Lab, Physics and Astronomy, Iowa State University/Ames Laboratory, Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames Lab/Iowa State, Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, USA, Iowa State University, Ames Laboratory and Iowa State University, Ames, IA USA 50011, Ames Laboratory/Iowa State University

  • Liqin Ke

    Ames Laboratory, Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, USA, Iowa State University, Ames Laboratory, U.S. Department of Energy

  • Peter Orth

    Dept. of Physics and Astronomy, Iowa State University, Iowa State University, Ames Laboratory and Iowa State University