FeSe and the missing electron pocket problem
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.
Citation
Rhodes , L C , Eschrig , M , Kim , T K & Watson , M D 2022 , ' FeSe and the missing electron pocket problem ' , Frontiers in Physics , vol. 10 , 859017 . https://doi.org/10.3389/fphy.2022.859017
Publication
Frontiers in Physics
Status
Peer reviewed
ISSN
2296-424XType
Journal article
Rights
Copyright © 2022 Rhodes , Eschrig , Kim and Watson . This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Description
LR acknowledges funding from the Royal Commission for the Exhibition 1851.Collections
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