Breaking Lorentz Reciprocity in the Weyl Semimetal Co<sub>3</sub>Sn<sub>2</sub>S<sub>2</sub> to Enable Time-Asymmetric Photonics

ORAL

Abstract

Weyl semimetals that break time-reversal symmetry are predicted to exhibit giant magneto-optical effects, the optical response from which can be described using an axion electrodynamics formalism. The formalism produces a dielectric tensor with non-vanishing off-diagonal components even without external magnetic fields; thus, these systems are interesting examples of violations of Lorentz reciprocity and Kirchhoff’s Law in small form factors.
Here we use electromagnetic and ab initio simulations, and experimental measurements of infrared light scattering to demonstrate the breaking of Lorentz reciprocity in the ferromagnetic phase of Co3Sn2S2 through calculations and measurement of nonequivalent reflection coefficients of opposing channels. We measure, via ellipsometry, the components of the dielectric tensor and discuss the implications of this result on the feasibility of magnetic Weyl semimetals for time-asymmetric photonics applications.

[1] B. Zhao, et al., Nano Lett, 20, 3, 1923-1927(2020).
[2] D. M. Nenno, et al., Nat Rev Phys (2020).

*- Department of Energy ‘Photonics at Thermodynamic Limits’ Energy Frontier Research Center Grant No DE-SC0019140
- Department of Energy Office of Science National Energy Research Scientific Computing Center (NERSC) Contract No DE-AC02-05CH11231

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Presenters

  • Arun Nagpal

    • Applied Physics and Materials Science, California Institute of Technology

Authors

  • Arun Nagpal

    • Applied Physics and Materials Science, California Institute of Technology

  • Dennis Nenno

    • John A. Paulson School of Engineering & Applied Science, Harvard University
    • Harvard University

  • Christina Garcia

    • John A. Paulson School of Engineering & Applied Science, Harvard University
    • Harvard University
    • John A. Paulson School of Engineering and Applied Sciences, Harvard University

  • Chandra Shekhar

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for the Chemical Physics of Solids
    • Max Planck, Dresden
    • Max Planck Institute for Chemical Physics of Solids, 01187 Dresden

  • Claudia Felser

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for the Chemical Physics of Solids
    • Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute, Dresden, Germany
    • Max Planck, Dresden
    • Max Planck Institute for Chemical Physics of Solids, 01187 Dresden
    • Max Planck Institute for Chemical Physics of Solids,

  • Prineha Narang

    • Harvard University
    • SEAS, Harvard University
    • John A. Paulson School of Engineering & Applied Science, Harvard University
    • Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University
    • Physics, Harvard University
    • John A. Paulson School of Engineering and Applied Sciences, Harvard University

  • Harry Atwater

    • Caltech
    • Applied Physics and Materials Science, California Institute of Technology