Elucidation of phase diagram and mechanism of superconductivity in strongly correlated multi-orbital electron systems

2016 Fiscal Year Final Research Report

• Project/Area Number: 26800185
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Okayama University
• Principal Investigator: Onari Seiichiro 岡山大学, 異分野基礎科学研究所, 准教授 (80402535)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 超伝導 / 強相関電子系 / 軌道秩序

Outline of Final Research Achievements

In this study, the universal understanding of whole phase diagram in iron-based superconductors particularly progresses. Iron-based superconductors with high superconducting transition temperature were first discovered in Japan. By using the self-consistent vertex correction (SC-VC) method, which we had newly developed, it has been cleared that the new interaction between spin and orbital is induced by the vertex correction, and the orbital fluctuations increase mutually with the spin fluctuations.
From this result, spin order, orbital order, and superconductivity in phase diagram of iron-based superconductors are understood independently of materials by the vertex correction. In addition, the peculiar wavenumber dependence of orbital polarization energy in the orbital-ordered phase of iron-based superconductors observed in experiments is reproduced independently of materials by the theory based on the SC-VC method.

Free Research Field

物性理論