Theoretical prediction of a two-dimensional in-plane antiferromagnetic insulator

ORAL

Abstract

Recent discovery of two-dimensional (2D) magnetic materials has brought magnetism to the flatland and opened up exciting opportunities for the exploration of fundamental physics as well as novel device applications. Here, we predict a thermodynamically stable 2D magnetic material, K2CoS2, which retains its in-plane bulk antiferromagnetic (AFM) order down to the monolayer and bilayer limits [1]. Magnetic moments (2.5 μB/Co) are found to form a quasi-one-dimensional antiferromagnetically ordered chain of Co atoms. The nonmagnetic electronic spectrum of the monolayer film is found to host flatbands and van Hove singularities, which play a key role in stabilizing the magnetic ground state. Based on classical Monte Carlo simulations, we estimate the Neel temperature for the AFM monolayer to be ≈ 15 K. Our study demonstrates that K2CoS2 hosts a robust AFM state which persists from the monolayer limit to the bulk material.

[1] Anan Bari Sarkar et. al, Phys. Rev. B 102, 035420 (2020).

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Presenters

  • Anan Bari Sarkar

    • Department of Physics, Indian Institute Of Technology Kanpur

Authors

  • Anan Bari Sarkar

    • Department of Physics, Indian Institute Of Technology Kanpur

  • Barun Ghosh

    • Department of Physics, Indian Institute Of Technology Kanpur
    • Department of Physics, Indian Institute of Technology Kanpur, India
    • Department of Physics, Indian Institute of Technology Kanpur

  • Bahadur Singh

    • DCMPMS, Tata Institute of Fundamental Research
    • Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research
    • Northeastern University
    • TIFR

  • Somnath Bhowmick

    • DMSE, Indian Institute of Technology Kanpur

  • Hsin Lin

    • Institute of Physics, Academia Sinica
    • Academia Sinica
    • Institute of Physics, Academia Sinica, Taipei
    • Institute of Physics, Academia Sinica, Taiwan
    • Physics, Academia Sinica

  • Arun Kumar Bansil

    • Department of Physics, Northeastern University
    • Northeastern University
    • Northeastern U

  • Amit Agarwal

    • Department of Physics, Indian Institute Of Technology Kanpur
    • Indian Institute of Technology
    • Department of Physics, Indian Institute of Technology Kanpur, India
    • Department of Physics, Indian Institute of Technology Kanpur