Abstract
We demonstrate a unidirectional motion of a quasiparticle without explicit symmetry breaking along the space-time coordinate of the particle motion. This counterintuitive behavior originates from a combined action of two intrinsic asymmetries in the other two directions. We realize this idea with the magnon-driven motion of a magnetic domain wall in thin films with interfacial asymmetry. Contrary to previous studies, the domain wall moves along the same direction regardless of the magnon-flow direction. Our general symmetry analysis and numerical simulation reveal that the odd order contributions from the interfacial asymmetry is unidirectional, which is dominant over bidirectional contributions in the realistic regime. We develop a simple analytic theory on the unidirectional motion, which provides an insightful description of this counterintuitive phenomenon.
| Original language | English (US) |
|---|---|
| Journal | Physical Review Letters |
| Volume | 122 |
| Issue number | 14 |
| DOIs | |
| State | Published - Apr 9 2019 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: We acknowledge A. Thiaville, P. Pirro, and S.-K. Kim for fruitful discussions. This work is supported by NRF (2015M3D1A1070465, 2017R1A2B2006119) and the KIST Institutional Program (No. 2V05750 and No. 2E29410). The work in Mainz was supported by the Alexander von Humboldt Foundation, the ERC Synergy Grant SC2 (No. 610115), the Transregional Collaborative Research Center (SFB/TRR) 173, and the German Research Foundation (DFG) (No. EV 196/2-1 and No. SI 1720/2-1). K.W.K was also supported by the National Research Council of Science & Technology (NST) (Grant No. CAP-16-01-KIST). H.W.L. was supported by NRF (2018R1A5A6075964). A.M. acknowledges support from the King Abdullah University of Science and Technology (KAUST).