Coexistence of non-Fermi and Fermi liquid near quantum critical point

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05152
• 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: Japan Atomic Energy Agency
• Principal Investigator: Kambe Shinsaku 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 先端基礎研究センター, 研究主席 (40224886)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 量子臨界 / NMR

Outline of Final Research Achievements

The magnetic field and temperature dependence of spin echo decay of heavy electron system YbRh2Si2 were measured using high quality single crystal samples. A high quality single crystal YbRh2Si2 sample was prepared by concentrating the 29 Si isotope by 52%. Since the natural abundance ratio of 29 Si isotope is about 4%, this enrichment can shorten the measured integrated time to about one hundredth. Using this single crystal sample, NMR spin echo decay was measured. In the decay curve, an ordinary Gauss type and Lorentz type decays are observed, in addition, a clear oscillation term appeared. This is thought to be due to the RK interaction and quasi-dipolar interaction. A significant frequency change was observed below 20 K. This indicates that there is a large change in the Fermi surface at 20 K or less. In YbRh2Si2, though it was thought that there is no large Fermi surface change down to 70 mK, this study revealed that there is a change from higher temperature.

Free Research Field

固体物性物理