Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields
Achieving control over magnon spin currents in insulating magnets, where dissipation due to Joule heating is highly suppressed, is an active area of research that could lead to energy-efficient spintronics applications. However, magnon spin currents supported by conventional systems with uniform mag...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-02-01
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| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.2.013231 |
| _version_ | 1797211519508807680 |
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| author | Sebastián A. Díaz Tomoki Hirosawa Jelena Klinovaja Daniel Loss |
| author_facet | Sebastián A. Díaz Tomoki Hirosawa Jelena Klinovaja Daniel Loss |
| author_sort | Sebastián A. Díaz |
| collection | DOAJ |
| description | Achieving control over magnon spin currents in insulating magnets, where dissipation due to Joule heating is highly suppressed, is an active area of research that could lead to energy-efficient spintronics applications. However, magnon spin currents supported by conventional systems with uniform magnetic order have proven hard to control. An alternative approach that relies on topologically protected magnonic edge states of spatially periodic magnetic textures has recently emerged. A prime example of such textures is the ferromagnetic skyrmion crystal which hosts chiral edge states providing a platform for magnon spin currents. Here we uncover that an external magnetic field can drive a topological phase transition in the spin-wave spectrum of a ferromagnetic skyrmion crystal. The topological phase transition is signaled by the closing of a low-energy bulk magnon gap at a critical field. In the topological phase, below the critical field, two topologically protected chiral magnonic edge states lie within this gap, but they unravel in the trivial phase, above the critical field. Remarkably, the topological phase transition involves an inversion of two magnon bands that at the Γ point correspond to the breathing and counterclockwise modes of the skyrmions in the crystal. Our findings suggest that an external magnetic field could be used as a knob to switch on and off magnon spin currents carried by topologically protected chiral magnonic edge states. |
| first_indexed | 2024-04-24T10:27:47Z |
| format | Article |
| id | doaj.art-26fc34e104e94b71a018cf4932430812 |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:27:47Z |
| publishDate | 2020-02-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-26fc34e104e94b71a018cf49324308122024-04-12T16:50:38ZengAmerican Physical SocietyPhysical Review Research2643-15642020-02-012101323110.1103/PhysRevResearch.2.013231Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fieldsSebastián A. DíazTomoki HirosawaJelena KlinovajaDaniel LossAchieving control over magnon spin currents in insulating magnets, where dissipation due to Joule heating is highly suppressed, is an active area of research that could lead to energy-efficient spintronics applications. However, magnon spin currents supported by conventional systems with uniform magnetic order have proven hard to control. An alternative approach that relies on topologically protected magnonic edge states of spatially periodic magnetic textures has recently emerged. A prime example of such textures is the ferromagnetic skyrmion crystal which hosts chiral edge states providing a platform for magnon spin currents. Here we uncover that an external magnetic field can drive a topological phase transition in the spin-wave spectrum of a ferromagnetic skyrmion crystal. The topological phase transition is signaled by the closing of a low-energy bulk magnon gap at a critical field. In the topological phase, below the critical field, two topologically protected chiral magnonic edge states lie within this gap, but they unravel in the trivial phase, above the critical field. Remarkably, the topological phase transition involves an inversion of two magnon bands that at the Γ point correspond to the breathing and counterclockwise modes of the skyrmions in the crystal. Our findings suggest that an external magnetic field could be used as a knob to switch on and off magnon spin currents carried by topologically protected chiral magnonic edge states.http://doi.org/10.1103/PhysRevResearch.2.013231 |
| spellingShingle | Sebastián A. Díaz Tomoki Hirosawa Jelena Klinovaja Daniel Loss Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields Physical Review Research |
| title | Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields |
| title_full | Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields |
| title_fullStr | Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields |
| title_full_unstemmed | Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields |
| title_short | Chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields |
| title_sort | chiral magnonic edge states in ferromagnetic skyrmion crystals controlled by magnetic fields |
| url | http://doi.org/10.1103/PhysRevResearch.2.013231 |
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