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Prediction of Anti-Kramers Antiferromagnetism (AKAF) in doped FeSb<sub>2</sub>

ORAL

Abstract

A new phenomenon, overlooked for decades, here called AKAF, was recently discussed by several groups. It represent a fully compensated antiferromagnet with no net magnetization, which nonetheless manifests time-reversal symmetry breaking typical of ferromagnets: exchange band splitting, anomalous Hall effect (AHE), and magneto-optical Kerr effect (MOKE). In this talk we concentrate on a well known semiconductor, FeSb2, and show several highly unexpected features: (1) DFT ground state is not paramagnetic, and not, as suggested by some, ferro-, but antiferromagnetic (AF); (2) two different AF exist, and the most stable one corresponds to the so-called AFMe order, observed experimentally in CrSb2 (which is NOT AKAF); (3) the energetically favorable AKAF state is metallic, and the nonmagnetic one semiconducting, which is highly unusual; (4) the AFMe order is preferential to the AKAF one, since it has a pseudogap at EF. and the paramagnetic one is realized in nature because of the gap opening; (5) doping with Cr or Co reduces the advantage of (pseudo-)gapping, and in a narrow range of doping the AKAF becomes the ground state. We calculate AHE and MOKE, which appear nonzero for two magnetization directions, including the DFT easy axis.

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Presenters

  • Igor Mazin

    Physics & Astronomy, George Mason University, Department of Physics and Astronomy, George Mason University, George Mason University, Physics and Astronomy, George Mason University, Physics, George Mason University, Department of Physics and Astronomy,, George Mason University, Department of Physics and Astronomy and Quantum Science and Engineering Center, George Mason University – Fairfax, VA, USA

Authors

  • Igor Mazin

    Physics & Astronomy, George Mason University, Department of Physics and Astronomy, George Mason University, George Mason University, Physics and Astronomy, George Mason University, Physics, George Mason University, Department of Physics and Astronomy,, George Mason University, Department of Physics and Astronomy and Quantum Science and Engineering Center, George Mason University – Fairfax, VA, USA

  • Libor Smejkal

    Institute of Physics, Johannes Gutenberg-Universitat Mainz, Germany, Johannes Gutenberg-Universität Mainz, Uni Mainz

  • Michelle Dawn Johannes

    Naval Research Laboratory

  • Rafael J Gonzalez-Hernandez

    Departamento de Fisica, Universidad del Norte, Barranquilla, Colombia

  • Klaus Koepernik

    Leibniz-Institute for Solid State and Materials Research, IFW Dresden