Scattering of Magnons at Graphene Quantum-Hall-Magnet Junctions

Nemin Wei, Chunli Huang, Allan H. Macdonald

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


Motivated by recent nonlocal transport studies of quantum-Hall-magnet (QHM) states formed in monolayer graphene's N=0 Landau level, we study the scattering of QHM magnons by gate-controlled junctions between states with different integer filling factors ν. For the ν=1|-1|1 geometry we find that 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 ν=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 nonlocal-voltage signals observed in the ν=1|0|1 case. We use our theory to propose that valley waves generated at ν=-1|1 junctions and magnons can be used in combination to probe the spin or valley flavor structure of QHM states at integer and fractional filling factors.

Original languageEnglish
Article number117203
JournalPhysical Review Letters
Issue number11
StatePublished - Mar 18 2021

Bibliographical note

Funding Information:
We acknowledge helpful interactions with Hailong Fu, Andrea Young, Haoxin Zhou, and Jun Zhu. This work is supported by DOE BES Grant No. DE- FG02-02ER45958 and by Welch Foundation Grant No. TBF1473. N. W was partially supported by a Graduate School Continuing Fellowship.

Publisher Copyright:
© 2021 American Physical Society.

ASJC Scopus subject areas

  • Physics and Astronomy (all)


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