APS Logo

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).

–

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