Numerical study of quantum spin systems on the basis of Majorana fermion picture

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K13533
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: The University of Tokyo
• Principal Investigator: Motome Yukitoshi 東京大学, 大学院工学系研究科(工学部), 教授 (40323274)
• Co-Investigator(Kenkyū-buntansha): 那須 譲治 東京工業大学, 理学院, 助教 (40610639) ; 宇田川 将文 学習院大学, 理学部, 准教授 (80431790) ; 加藤 康之 東京大学, 大学院工学系研究科(工学部), 助教 (50708534)
• Research Collaborator: Knolle Johannes ; Moessner Roderich ; YOSHITAKE Junki ; Mishchenko Petr A.
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 強相関電子系 / 計算物理 / 量子スピン系 / トポロジー

Outline of Final Research Achievements

In this project, we have developed new numerical methods for clarifying the nature of exotic quantum phases of magnets, quantum spin liquids. On the basis of the Majorana fermion picture used in the exact solution for the so-called Kitaev model, we developed a new quantum Monte Carlo method, dynamical mean-field approximation, and continuous-time quantum Monte Carlo method. By utilizing the new methods, we clarified the temperature and energy dependences of various physical quantities. From the comparison with the experimental data for candidate materials for the Kitaev model, we provided strong evidences for the realization of quantum spin liquids in these materials.

Free Research Field

物性理論