| 研究課題/領域番号 |
18K04941
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| 研究機関 | 九州大学 |
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研究代表者 |
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| 研究期間 (年度) |
2018-04-01 – 2021-03-31
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| キーワード | spin-orbit coupling / Rashba effect / SiC / graphene / triangular lattice |
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| 研究実績の概要 |
In accordance with research plan for 2019, we have continued investigating dense triangular lattice atomic overlayers (TLALs) of group III, IV, and V heavy elements on SiC(0001) by experimental and computational methods. The following has results have been achieved:
1. The additional computation have boon carried out to check how much of a role SiC substrate play in formation and stability of triangular lattices. We have found that using silicon nitride surface, lacking dangling bonds the stability of TLALs are significantly compromised giving way to honeycomb lattices rather than triangular.
2. Experimental environment has been improved to allow better sample preparation technique and accurate LEED/RHEED analysis. Refurbished STM machine has been set, but not operational yet. New advanced experimental methods (SPA-LEED, momentum microscope) at collaborative sites (Institute of Molecular Sciences) has been tested on other simpler systems to ensure possibility to work on the TLAL systems in future.
3. STM measurement on graphene/Sn/SiC system has been carried out. Surprisingly some periodic modulations larger than 1x1 and with an unexpected symmetry have been observed. Currently the situation has been investigated on possibility of graphene interference.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
The experimental part of the research is delaying slightly from the planned pace. The reasons are complications with equipment preparation (sample preparation and LEED analysis part should be resolved next year, the STM machine which we were hoped to use for experiments has been largely mulfunctioned and require lots of repairs) and active involvement in other graphene related projects. The publication preparation of important initial results also has delayed research activity to some extent.
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| 今後の研究の推進方策 |
As experimental environment seems to improve next year we are planning to attack the goals of our proposed research. In particular the TLAL structures of In and Sb will be attempted to grow as they are predicted to be stable and show peculiar electronic spin states close to Fermi level with is advantageous for electronic devices. The samples will be analyzed by various techniques and results will be published in scientific journal.
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| 次年度使用額が生じた理由 |
Previous fiscal year the research was delayed slightly due to large involvement in other research projects and analyzing previous data. Although experimental setup was also performed, it was in smaller scale than expected. So, the majority of unused funds were from article costs. Next fiscal year more equipment upgrades and modifications are planned to provide adequate environment for experimental part of research to be accelerated to achieve planned goals. In particular we plan on modifying sample preparation system by introducing additional level of control and automation, and also reviving STM machine, for which some critical parts has to be replaced.
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