Computational study of phase transitions induced by topological defects

2016 Fiscal Year Final Research Report

• Project/Area Number: 25287097
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: The University of Tokyo
• Principal Investigator: KAWASHIMA Naoki 東京大学, 物性研究所, 教授 (30242093)
• Research Collaborator: HARADA Kenji 京都大学, 大学院情報学研究科, 助教 ; WATANABE Hiroshi 東京大学, 物性研究所, 助教 ; SUZUKI Takafumi 兵庫県立大学, 大学院工学研究科, 准教授 ; OKUBO Tsuyoshi 東京大学, 物性研究所, 特任研究員 ; MASAKI Akiko 理化学研究所, 特任研究員 ; OSHIKAWA Kosei 東京大学, 理学系研究科 ; KIRII Tomohiro 東京大学, 理学系研究科
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 計算物理学 / 量子モンテカルロ / ボーズ凝縮 / 光格子 / 超流動 / テンソルネットワーク

Outline of Final Research Achievements

Firstly, we found a second-order phase transition accompanied by the dissociation of Z2 vortex pairs in the Heisenberg model on the triangular lattice. This phase transition turned out to be in the universality class of the 2D Ising model. Secondly, we studied the vortex dissociation transition in the SU(N) JQ model and found that the estimate of the critical indices constantly drift as the system size increases. Thirdly, we developed new methods and codes for the vortex dissociation transitions in quantum many body systems, e.g., the parallelizable worm algorithm for quantum Monte Carlo.

Free Research Field

計算統計物理学