2015 Fiscal Year Research-status Report
Topological Transitions in Spin Transport in Nanostructures
| Project/Area Number |
26390014
|
|---|
| Research Institution | Institute of Physical and Chemical Research |
|---|
Principal Investigator |
サーリコスキ ヘンリー 国立研究開発法人理化学研究所, 創発物性科学研究センター, 研究員 (50722245)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
多々良 源 国立研究開発法人理化学研究所, その他部局等, その他 (10271529)
|
|---|
| Project Period (FY) |
2014-04-01 – 2017-03-31
|
| Keywords | spin / spintronics / topology / magnetism / antiferromagnet |
|---|
| Outline of Annual Research Achievements |
The research project has focused on topological effects in spin interference and has progressed very well as planned. This fiscal year a research paper titled "Effective geometric phases and topological transitions in SO(3) and SU(2) rotations" has been published in Journal of Physics: Condensed Matter (http://dx.doi.org/10.1088/0953-8984/28/16/166002). The paper describes a surprising analogy between classical systems and quantum spin systems and shows that topological transition is related to geometry of rotations in both cases. This research result has been reported in a number of conferences, e.g. in a German Physical Society meeting in Regensburg March 2016 and Japanese Physical Society Meeting in Sendai March 2016.
In addition to this progress in spin the project has focused on spin effects in metals and a manuscript on domain wall motion in synthetic antiferromagnets was prepared in collaboration with experimentalists at University of Leeds and submitted to Nature Nanotechnology. A preprint is available at http://arxiv.org/abs/1604.07992
A central finding in this work a huge reduction in the threshold current in such synthetic antiferromagnets in comparison to single-layer ferromagnetic systems. Theoretical modeling performed in this project indicated that this is due to strongly anisotropic layer coupling in the presence of nonadiabatic driving. The results were presented in the MMM-Intermag meeting in San Diego in January 2016.
JSPS funding was acknowledged in these papers/manuscripts and during talks.
|
| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
The surprising results have lead to the above papers/manuscripts and have opened new prospects for future research.
|
| Strategy for Future Research Activity |
Plans for future include collaboration with Junsaku Nitta's group towards experimental realisation of our predicted topological effects in spin interference. In addition details of the theoretical work indicating stability of the topological transition will be published in a follow-up paper. Moreover, the project will in future focus on larger quantum networks where spin interference effects would be more intricate and lead to complex effects. These are computationally heavier and will be performed at Hokusai supercomputers at the Advanced Center for Computing and Communications (ACCC) at RIKEN.
|
| Causes of Carryover |
A bit of funding (5%) was left over to the next fiscal year.
|
| Expenditure Plan for Carryover Budget |
The incurring amount will be used for travelling to conferences.
|
Research Products
(4 results)
