Correlations in Iron-based Superconductors:An ARPES Perspective
Lin, Ping-Hui1,2*
1National Synchrotron Radiation Research Center, HsinChu, Taiwan
2Department of Physics, National Tsing Hua University, HsinChu, Taiwan
* presenting author:Ping-Hui Lin, email:lin.pinghui@nsrrc.org.tw
The connection between the magnetism, superconductivity and the implicit correlation effects linked to the orbital degeneracy in iron-based superconductors have become an intriguing topic in condensed matter physics. Theoretical calculations suggest that Hund’s couplings could induce new types of correlations, which tend to align spins of electrons in different orbitals. The level of the electrons moments’ localization, rather than being itinerant, seems to be responsible for the transport behavior of the material¹.

Angle-resolved photoelectron spectroscopy (ARPES) has been used to study a large number of iron-based compounds in both their magnetic and paramagnetic states, providing direct observation of the electronic structures² ³. An overall normalization factor of 2-4 compared to the DFT calculation is considered to be the indication of correlation strength in different families of iron-based superconductors⁴ ⁵. Moreover, thorough analysis of ARPES data, further, evidences the differential correlation strength on the orbitals in iron-based superconductors.

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Keywords: Fe-based superconductors, Strongly Correlated Systems, ARPES