Theoretical study of strongly correlated electron systems on geometrically frustrated lattices

2014 Fiscal Year Final Research Report

• Project/Area Number: 24740221
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: UDAGAWA Masafumi 東京大学, 工学(系)研究科(研究院), 助教 (80431790)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 幾何学的フラストレーション / 量子ホール効果 / スピンアイス

Outline of Final Research Achievements

In this project, I have carried out an extensive analysis on electronic systems on a pyrochlore lattice, one of the lattices classified as complete graph, and obtained several important results. Firstly, we gave an explanation to various properties in a magnetically ordered phase, with all-in/all-out type magnetic order, by focusing on the role of domain walls, and also discussed the controllability of domain wall with electric current. Secondly, I discussed the possible existence of composite excitation, which we call monopole ring, in itinerant spin ice system, and also proposed that this monopole ring excitation may explain the spontaneous Hall effect observed in Pr2Ir2O7. And thirdly, I showed the possible existence of Abelian and non-Abelian fractional quantum Hall effect on the surface of layered pyrochlore systems, as a result of interplay between electron interaction and topological nature of the surface inherited from the Weyl semimetal state realized in the bulk.

Free Research Field

物性物理学理論