FeSe and the missing electron pocket problem

DOI: 10.3389/fphy.2022.859017

Authors: Luke C. Rhodes (University of St. Andrews) , Matthias Eschrig (University of Greifswald) , Timur K. Kim (Diamond Light Source) , Matthew D. Watson (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Frontiers In Physics , VOL 10

State: Published (Approved)
Published: May 2022

Abstract: The nature and origin of electronic nematicity remains a significant challenge in our understanding of the iron-based superconductors. This is particularly evident in the iron chalcogenide, FeSe, where it is currently unclear how the experimentally determined Fermi surface near the M point evolves from having two electron pockets in the tetragonal state, to exhibiting just a single electron pocket in the nematic state. This has posed a major theoretical challenge, which has become known as the missing electron pocket problem of FeSe, and is of central importance if we wish to uncover the secrets behind nematicity and superconductivity in the wider iron-based superconductors. Here, we review the recent experimental work uncovering this nematic Fermi surface of FeSe from both ARPES and STM measurements, as well as current theoretical attempts to explain this missing electron pocket of FeSe, with a particular focus on the emerging importance of incorporating the dxy orbital into theoretical descriptions of the nematic state. Furthermore, we will discuss the consequence this missing electron pocket has on the theoretical understanding of superconductivity in this system and present several remaining open questions and avenues for future research.

Journal Keywords: FeSe; ARPES; electronic structure; superconductivity; nematicity; strong correlations; iron based superconductors

Subject Areas: Materials, Physics


Technical Areas: Theoretical Physics

Added On: 01/06/2022 11:58

Documents:
fphy-10-859017.pdf

Discipline Tags:

Superconductors Quantum Materials Physics Hard condensed matter - structures Materials Science Theoretical Physics

Technical Tags: