Microscopic investigation of field-induced superconducting mechanism in itinerant ferromagnetic superconductors

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400375
• 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: TOKUNAGA Yo 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, 研究主幹 (00354902)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 強磁性超伝導 / 核磁気共鳴 / 量子臨界点 / 磁場誘起超伝導 / 三重臨界点

Outline of Final Research Achievements

The re-entrant superconductivity (RSC), discovered in 2005, emerges near a field-induced quantum critical point (QCP) in a ferromagnetic (FM) superconductor URhGe. While the origin of this RSC is broadly thought to be associated with quantum critical fluctuations near the QCP, their exact nature had not been well identified. In this study, we conducted 59Co NMR study in a Co-doped single crystal of URhGe. The experiment revealed a divergence of electronic spin fluctuations in the vicinity of the QCP. Furthermore, the fluctuations observed are characteristic of a tricritical point. We have suggested these fluctuations as the pairing glue responsible for the RSC.

Free Research Field

固体物理