2017 Fiscal Year Research-status Report
antiferromagnetic magnon spin valve
| Project/Area Number |
17K14331
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| Research Institution | Tohoku University |
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Principal Investigator |
侯 達之 東北大学, 材料科学高等研究所, 助教 (00704355)
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| Project Period (FY) |
2017-04-01 – 2019-03-31
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| Keywords | spintronics / antiferromagnet / spin valve / spin transistor |
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| Outline of Annual Research Achievements |
In the 2017 fiscal year, both theoretical and experimental approaches were employed to achieve the antiferromagnetic magnon spin valve. Here is the published or accepted paper in FY2017 with some brief summary.
1. Spin colossal magnetoresistance in an antiferromagnetic insulator Z Qiu, D. Hou*, J. Barker, K. Yamamoto, O. Gomonay, E. Saitoh, arXiv:1804.04516. (Nature Materials in press) We succeed to manipulate the spin transmission of an antiferromagnetic insulator by external magnetic field which rotates the Neel vector.
2. The bimodal distribution spin Seebeck effect enhancement in epitaxial Ni0. 65Zn0. 35Al0. 8Fe1. 2O4 thin film, H. Wang, D. Hou* et al., Applied Physics Letters 112 (14), 142406 (2018) Magnetic field induced enhancement of the spin Seebeck effect is observed in a non-garnet ferromagnetic insulator Ni0. 65Zn0. 35Al0. 8Fe1. 2O4.
3. Magnon detection using a ferroic collinear multilayer spin valve, J. Cramer et al., Nature communications 9 (1), 1089 (2018) In a ferromagnet/antiferromagnet/ferromagnet trilayer system, difference in the spin pumping signal is observed for parallel and anti-parallel relative orientation of the two ferromagnet electrode.
4. Antiferromagnetic anisotropy determination by spin Hall magnetoresistance, H. Wang, D. Hou*, Z. Qiu, T. Kikkawa, E. Saitoh, X. Jin, Journal of Applied Physics 122 (8), 083907 (2017) The spin Hall magnetoresistance in a Pt/antiferromagnet insulator structure is calculated, which provides a new approach for the determination of the antiferromagnetic anisotropy.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We designed two types of devices to realize the magnon spin valve experimentally: Pt/Cr2O3/YIG and Pt/CoO/NZAF. Pt serves as a spin current detector by the inverse spin Hall effect. YIG and NZAF serve as spin current source from which spin current can be driven out and injected into antiferromagnets.
The key step for the demonstration of magnon spin valve in antiferromangets is to control the Neel vector orientation. For Cr2O3, the Neel vector can be tilted by an external magnetic field. For CoO, the Neel vector can be set along either of the inplane easy axis by field cooling. Now the experiment for both types of devices are completed. The work on Cr2O3 has been accepted by Nature Materials. The work on CoO has been completed and the manuscript is under preparation.
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| Strategy for Future Research Activity |
In FY2018, more systematic measurement will be arranged for Pt/Cr2O3/YIG and Pt/CoO/NZAF. Several issues will be settled:
1. From our present understanding, the spin current control in Cr2O3 is achieved by the rotation of Neel vector. So it should be possible to see much larger effect at low temperature where the antiferromagnetic order has been fully established.
2. The CoO thickness dependence is crucial for the understanding of the spin current transmission. The issue is under a spin-flop coupling between NZAF and CoO, does the spin transmission stay finite at higher temperature or it nearly vanishes below the Neel temperature? It is a very important problem for the real device design.
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| Causes of Carryover |
Mainly to support the international conference and visit to share our recent progress to international researchers.
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Research Products
(7 results)
