Electrically tunable long-distance transport in crystalline antiferromagnetic iron oxide

Spintronics uses spins, the intrinsic angular momentum of electrons, as an alternative for the electron charge. Its long-term goal is to develop beyond-Moore, low-dissipation technology devices, recently demonstrating long-distance transport of spin signals across ferromagnetic insulators 1 . Antife...

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Bibliographic Details
Published in:Nature (London) 2018-09, Vol.561 (7722), p.222-225
Main Authors: Lebrun, R., Ross, A., Bender, S. A., Qaiumzadeh, A., Baldrati, L., Cramer, J., Brataas, A., Duine, R. A., Kläui, M.
Format: Article
Language:English
Online Access:Get full text
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Summary:Spintronics uses spins, the intrinsic angular momentum of electrons, as an alternative for the electron charge. Its long-term goal is to develop beyond-Moore, low-dissipation technology devices, recently demonstrating long-distance transport of spin signals across ferromagnetic insulators 1 . Antiferromagnetically ordered materials, the most common class of magnetic materials, have several crucial advantages over ferromagnetic systems 2 . Antiferromagnets exhibit no net magnetic moment, rendering them stable and impervious to external fields. Additionally, they can be operated at THz frequencies 3 . Although their properties bode well for spin transport 4 – 7 , previous indirect observations indicate that spin transmission through antiferromagnets is limited to only a few nanometers 8 – 10 . Here we demonstrate the long-distance propagation of spin-currents through single-crystalline hematite (α-Fe 2 O 3 ) 11 , the most common antiferromagnetic iron oxide, exploiting the spin Hall effect for spin injection. We control the spin-current flow by the interfacial spin-bias, tuning the antiferromagnetic resonance frequency with an external magnetic field 12 . This simple antiferromagnetic insulator conveys spin information parallel to the Néel order over distances exceeding tens of micrometers. This newly-discovered mechanism transports spin as efficiently as the net magnetic moments in the best-suited complex ferromagnets 1 . Our results pave the way to ultra-fast, low-power antiferromagnet-insulator-based spin-logic devices 6 , 13 that operate, without magnetic fields, at room temperature.
ISSN:0028-0836
1476-4687
DOI:10.1038/s41586-018-0490-7