Fermiology of d-electron mutiband superconductors

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400373
• 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: National Institute for Materials Science
• Principal Investigator: TERASHIMA Taichi 国立研究開発法人物質・材料研究機構, 機能性材料研究拠点, 主席研究員 (40343834)
• Research Collaborator: KIKUGAWA Naoki
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: フェルミ面 / 量子振動 / 超伝導

Outline of Final Research Achievements

We performed quantum oscillation measurements on SrPt3P and observed part of the Fermi surface. The mass enhancement factors are between 0 and 0.9 for the observed orbits. On the other hand, the Sommerfeld coefficient reported previously suggests the enhancement factor averaged over the whole Fermi surface is approximately 1. This suggests that strong electron-phonon interactions exist on a part of the Fermi surface that is not yet observed.
We performed quantum oscillation measurements on FeSe and determined the Fermi surface. The determined Fermi surface significantly deviates from what band-structure calculations predict. The Fermi surface is anomalously small and the carrier number is approximately 0.01 per Fe, which is one order-of-magnitude smaller than predicted. This indicates that electron correlations that are not included in the calculations are important in determining the electronic structure of FeSe.

Free Research Field

固体物理学