Study of quantum phase transitions byangle resolved NMR under extreme conditions

2017 Fiscal Year Final Research Report

• Project/Area Number: 25287083
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: Takigawa Masashi 東京大学, 物性研究所, 教授 (10179575)
• Co-Investigator(Renkei-kenkyūsha): NAKATSUJI Satoru 東京大学, 物性研究所, 教授 (70362431) ; KITAGAWA Kentaro 東京大学, 理学系研究科, 講師 (90567661) ; HIROI Zenji 東京大学, 物性研究所, 教授 (30192719) ; UWATOKO Yoshiya 東京大学, 物性研究所, 教授 (40213524) ; YOSHIDA Makoto 東京大学, 物性研究所, 助教 (40379475)
• Project Period (FY): 2013-04-01 – 2018-03-31
• Keywords: 核磁気共鳴 / 量子相転移 / 極限環境 / 量子スピン系 / 重い電子系

Outline of Final Research Achievements

In this study, we aimed at microscopic understanding of novel quantum phenomena caused by strong electronic correlation in transition-metal or rare-earth compounds, when they are placed in extreme environments such as strong magnetic field, high pressure, or very low temperatures, by using nuclear magnetic resonance technique. Regarding low dimensional spin systems with frustration, we succeeded in observing magnetization plateaus, quantization of magnetization in strong magnetic fields, and spin-nematic correlation caused by bound pairs of magnetic excitations. Concerning Pr compounds with non-magnetic doublet crystalline field ground state, we obtained microscopic direct evidence for symmetry breaking due to quarupole order and quantum phase transition between different order parameters induced by very small magnetic fields.

Free Research Field

核磁気共鳴法を用いた強相関電子系の量子現象の研究