Scattering of magnons at graphene quantum-Hall-magnet junctions

ORAL

Abstract

Motivated by recent non-local transport studies of quantum-Hall-magnet (QHM) states formed in monolayer graphene’s N = 0 Landau level (Wei et.al Science 362, 229-233; Zhou et.al Nature Physics 16, 154–158(2020)), we study the scattering of QHM magnons by gate-controlled junctions between states with different integer filling factors \nu. For the \nu = 1| − 1|1 geometry we find magnons are weakly scattered by electric potential variation in the junction region, and that the scattering is chiral when the junction lacks a mirror symmetry. For the \nu = 1|0|1 geometry, we find that kinematic constraints completely block magnon transmission if the incident angle exceeds a critical value. Our results explain the suppressed non-local-voltage signals observed in the \nu = 1|0|1 case.

*This work is supported by DOE BES grant DE- FG02-02ER45958 and by Welch foundation grant TBF1473. N.W was partially supported by a Graduate School Continuing Fellowship

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Presenters

  • Nemin Wei

    • University of Texas at Austin

Authors

  • Nemin Wei

    • University of Texas at Austin

  • Chunli Huang

    • University of Texas at Austin

  • Allan MacDonald

    • Physics, University of Texas at Austin
    • Physics Department, University of Texas at Austin
    • University of Texas at Austin
    • Department of physics, University of Texas at Austin
    • Department of Physics, University of Texas at Austin
    • University of Texas, Austin