Strain-induced topological charge density wave in monolayer NbSe<sub>2</sub>

ORAL

Abstract

Despite the progress made in the successful prediction of many classes of weakly-correlated topological materials, it is not clear whether a charge ordered topological state can exist in a two-dimensional (2D) material. Here, through first-principles modeling and analysis, we identify a 2×2 charge density wave (CDW) phase in monolayer 2H-NbSe2 that harbors coexisting quantum spin Hall (QSH) insulator, topological crystalline insulator (TCI), and topological nodal line (TNL) semimetal states. The topology in monolayer NbSe2 is driven by the formation of the CDW and the associated symmetry-breaking periodic lattice distortions and not via a pre-existing topology. Our finding of an emergent triple-topological state in monolayer 2H-NbSe2 will offer novel possibilities for exploring connections between different topologies and a unique materials platform for controllable CDW-induced topological states for potential applications in quantum electronics and spintronics.

*The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences Grant No. DE-SC0019275 (materials discovery for QIS applications) and benefited from Northeastern University's Advanced Scientific Computation Center and the National Energy Research Scientific Computing Center through DOE Grant No. DE-AC02-05CH11231. H.L. acknowledges the support by the Ministry of Science and Technology (MOST) in Taiwan under grant number MOST 109-2112-M-001-014-MY3. S.M. and A.A. gratefully acknowledge the HPC facility at the Indian Institute of Technology Kanpur, for computational resources. J.N. benefited from the resources of the Tampere Center for Scientific Computing, TCSC. T.H.'s research is supported by the ITU-BAP project TDK-2018-41181. T.-R.C. was supported by the Young Scholar Fellowship Program from the Ministry of Science and Technology (MOST) in Taiwan, under a MOST grant for the Columbus Program MOST110-2636-M-006-016, NCKU

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Publication: arXiv:2104.14634

Presenters

  • Wei-Chi Chiu

    • Northeastern University

Authors

  • Wei-Chi Chiu

    • Northeastern University

  • Sougata Mardanya

    • National Cheng Kung University

  • Robert S Markiewicz

    • Northeastern University

  • Jouko Nieminen

    • Tampere University

  • Bahadur Singh

    • Tata Institute of Fundamental Research
    • Tata Institute for Fundamental Research
    • TIFR
    • Tata Institute of Fundamental Research, Mumbai
    • Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India

  • Tugrul Hakioglu

    • Istanbul Technical University

  • Amit Agarwal

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

  • Tay-Rong Chang

    • Natl Cheng Kung Univ

  • Hsin Lin

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

  • Arun Bansil

    • Northeastern University
    • Department of Physics, Northeastern University, USA