TY - JOUR
T1 - Topological Magnon-Phonon Hybrid Excitations in Two-Dimensional Ferromagnets with Tunable Chern Numbers
AU - Go, Gyungchoon
AU - Kim, Se Kwon
AU - Lee, Kyung Jin
N1 - Funding Information:
K.-J.L. acknowledges support by the National Research Foundation (NRF) of Korea (NRF-2017R1A2B2006119). G.G. acknowledges a support by the NRF of Korea (NRF-2019R1I1A1A01063594). S.K.K. was supported by the startup fund at the University of Missouri.
PY - 2019/12/5
Y1 - 2019/12/5
N2 - We theoretically investigate magnon-phonon hybrid excitations in two-dimensional ferromagnets. The bulk bands of hybrid excitations, which are referred to as magnon polarons, are analytically shown to be topologically nontrivial, possessing finite Chern numbers. We also show that the Chern numbers of magnon-polaron bands and the number of band-crossing lines can be manipulated by an effective magnetic field. For experiments, we propose to use the thermal Hall conductivity as a probe of the finite Berry curvatures of magnon-polarons. Our results show that a simple ferromagnet on a square lattice supports topologically nontrivial magnon polarons, generalizing topological excitations in conventional magnetic systems.
AB - We theoretically investigate magnon-phonon hybrid excitations in two-dimensional ferromagnets. The bulk bands of hybrid excitations, which are referred to as magnon polarons, are analytically shown to be topologically nontrivial, possessing finite Chern numbers. We also show that the Chern numbers of magnon-polaron bands and the number of band-crossing lines can be manipulated by an effective magnetic field. For experiments, we propose to use the thermal Hall conductivity as a probe of the finite Berry curvatures of magnon-polarons. Our results show that a simple ferromagnet on a square lattice supports topologically nontrivial magnon polarons, generalizing topological excitations in conventional magnetic systems.
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U2 - 10.1103/PhysRevLett.123.237207
DO - 10.1103/PhysRevLett.123.237207
M3 - Article
C2 - 31868484
AN - SCOPUS:85076619076
VL - 123
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 23
M1 - 237207
ER -