Surface states at Anderson transitions in topological phases
| Project/Area Number |
25800213
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Mathematical physics/Fundamental condensed matter physics
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| Research Institution | Hokkaido University |
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Principal Investigator |
Obuse Hideaki 北海道大学, 工学(系)研究科(研究院), 助教 (50415121)
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Keywords | トポロジカル相 / アンダーソン転移 / 量子ウォーク / トポロジカル量子相 / 境界臨界性 / 弱いトポロジカル絶縁体 / directed network model / スケーリング次元 |
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| Outline of Final Research Achievements |
We have found that two-dimensional surface states of the three dimensional weak topological insulator with a stacked structure remain delocalized irrespective strength of disorder if hoppings between layers are homogeneous. However, if the hoppings between layers induce dimerization effects, electric states of the surface states show a localized-delocalized transition at a certain strength of disorder, whose universality class belongs to the two-dimensional symplectic class. We have also developed an efficient method to numerically calculate the scaling dimension of descendant operators at the two-dimensional integer quantum Hall transition. Furthermore, we have developed systematic procedures to identify symmetry and calculate topological numbers of time-evolution operators which could exhibit Floquet-topological phases. We have succeeded to explain the robustness of surface states of the one-dimensional quantum walk against disorder by using arguments of topological phases.
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Report
(4 results)
Research Products
(30 results)
