Magneto-reflectance study of Zeeman effect in MoS2 bilayer

ORAL

Abstract

We studied Zeeman splitting ΔE of different recombination channels in Bilayer MoS2 using magneto-reflectance spectroscopy. The Zeeman splitting of both A and B excitons of bilayer MoS2 is linear in magnetic field with a slope of approximately -0.2 meV/T similar to that of single layer MoS2. In addition, we observed a new feature labeled N at 2.01 eV between A (1.93 eV) and B (2.13 eV) excitons1. We note that feature N is not observed in MoS2 monolayers. This new feature shows a positive Zeeman slope of 0.37 meV/T as compared to A and B excitons. Theoretical2,3 and experimental4 studies show that bilayer MoS2 exhibits optical properties resulting from an interplay of the direct-bandgap of monolayer system, and the indirect bandgap of the bulk. A crucial property of the bilayer system appears to be its inversion symmetry2 and tuning3 of that symmetry translates into the interplay of contributions of different valleys in the photoluminescence spectra and possible appearance of additional emission4. We hypothesize that feature ‘N’ results from these valley-mixing effects.
1. K.F. Mak et al., Phys. Rev. Lett. 105, 136805 (2010)
2. E. S. Kadantsev and P. Hawrylak, Solid State Commun. 152, 909 (2012).
3. S. Wu et al., Nature Physics 9, 149 (2013)
4. T. Chu et al., Nano Lett. 15, 8000 (2015)

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Presenters

  • Tenzin Norden

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

Authors

  • Tenzin Norden

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Peiyao Zhang

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Arman Najafi

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Arinjoy Bhattacharya

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York

  • Marek J Korkusinski

    National Research Council - Canada, National Research Council of Canada

  • Athos Petrou

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York