TY - JOUR
T1 - Birefringence-like spin transport via linearly polarized antiferromagnetic magnons
AU - Han, Jiahao
AU - Zhang, Pengxiang
AU - Bi, Zhen
AU - Fan, Yabin
AU - Safi, Taqiyyah S.
AU - Xiang, Junxiang
AU - Finley, Joseph
AU - Fu, Liang
AU - Cheng, Ran
AU - Liu, Luqiao
N1 - Funding Information:
This work is supported in part by National Science Foundation under award no. ECCS-1808826, AFOSR, and by SMART, one of seven centres of nCORE, a Semiconductor Research Corporation programme, sponsored by National Institutes of Standards and Technology (NIST). The material synthesis and characterization are partially supported by the National Science Foundation under award no. DMR 14-19807 through the MRSEC shared facilities. J.H. thanks Y. Lin, P.-C. Shih and A.-Y. Lu for help with measurements.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - Antiferromagnets (AFMs) possess great potential in spintronics because of their immunity to external magnetic disturbance, the absence of a stray field or the resonance in the terahertz range1,2. The coupling of insulating AFMs to spin–orbit materials3–7 enables spin transport via AFM magnons. In particular, spin transmission over several micrometres occurs in some AFMs with easy-axis anisotropy8,9. Easy-plane AFMs with two orthogonal, linearly polarized magnon eigenmodes own unique advantages for low-energy control of ultrafast magnetic dynamics2. However, it is commonly conceived that these magnon modes are less likely to transmit spins because of their vanishing angular momentum9–11. Here we report experimental evidence that an easy-plane insulating AFM, an α-Fe2O3 thin film, can efficiently transmit spins over micrometre distances. The spin decay length shows an unconventional temperature dependence that cannot be captured considering solely thermal magnon scatterings. We interpret our observations in terms of an interference of two linearly polarized, propagating magnons in analogy to the birefringence effect in optics. Furthermore, our devices can realize a bi-stable spin-current switch with a 100% on/off ratio under zero remnant magnetic field. These findings provide additional tools for non-volatile, low-field control of spin transport in AFM systems.
AB - Antiferromagnets (AFMs) possess great potential in spintronics because of their immunity to external magnetic disturbance, the absence of a stray field or the resonance in the terahertz range1,2. The coupling of insulating AFMs to spin–orbit materials3–7 enables spin transport via AFM magnons. In particular, spin transmission over several micrometres occurs in some AFMs with easy-axis anisotropy8,9. Easy-plane AFMs with two orthogonal, linearly polarized magnon eigenmodes own unique advantages for low-energy control of ultrafast magnetic dynamics2. However, it is commonly conceived that these magnon modes are less likely to transmit spins because of their vanishing angular momentum9–11. Here we report experimental evidence that an easy-plane insulating AFM, an α-Fe2O3 thin film, can efficiently transmit spins over micrometre distances. The spin decay length shows an unconventional temperature dependence that cannot be captured considering solely thermal magnon scatterings. We interpret our observations in terms of an interference of two linearly polarized, propagating magnons in analogy to the birefringence effect in optics. Furthermore, our devices can realize a bi-stable spin-current switch with a 100% on/off ratio under zero remnant magnetic field. These findings provide additional tools for non-volatile, low-field control of spin transport in AFM systems.
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U2 - 10.1038/s41565-020-0703-8
DO - 10.1038/s41565-020-0703-8
M3 - Article
C2 - 32483320
AN - SCOPUS:85085593215
VL - 15
SP - 563
EP - 568
JO - Nature Nanotechnology
JF - Nature Nanotechnology
SN - 1748-3387
IS - 7
ER -