Characteristics and dynamics of spin nematic states in magnets

2015 Fiscal Year Final Research Report

• Project/Area Number: 23540397
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Momoi Tsutomu 国立研究開発法人理化学研究所, 古崎物性理論研究室, 専任研究員 (80292499)
• Co-Investigator(Renkei-kenkyūsha): SHINDOU Ryuichi 国立研究開発法人理化学研究所, 古崎物性理論研究室, 客員研究員 (60571932)
• Research Collaborator: Sindzingre Philippe ; Shannon Nic
• Project Period (FY): 2011-04-28 – 2016-03-31
• Keywords: 物性理論 / スピンネマティック相 / 三角格子 / ジグザグ鎖 / 多体スピン交換模型 / 動的物理量 / フラストレート磁性体 / 磁性

Outline of Final Research Achievements

Spin nematics are novel quantum states of matter, which possess both liquid-like character and solid-like magnetically ordered character. We studied the following theoretical models, thereby showing the existence of spin nematic phases: 1) the triangular-lattice multiple-spin exchange model for solid He 3 thin films, 2) a quasi-one-dimensional zigzag spin model for quasi one-dimensional cuprate spin systems, 3) a pyrochlore-lattice S=3/2 spin model for chromium spinel oxides.
To study magnetic excitations and dynamics in the spin nematic state, we constructed a mean-field theory. Taking account of fluctuations, we studied magnetic excitations, calculating the dynamical structure factor. We further derived temperature dependence of the NMR relaxation rate and the specific heat at low temperatures.

Free Research Field

物理学