Anomalous spectral weight transfer in the nematic state of iron-selenide superconductor

Abstract

Nematic phase intertwines closely with high-Tc superconductivity in iron-based superconductors. Its mechanism, which is closely related to the pairing mechanism of superconductivity, still remains controversial. Comprehensive characterization of how the electronic state reconstructs in the nematic phase is thus crucial. However, most experiments focus only on the reconstruction of band dispersions. Another important characteristic of electronic state, the spectral weight, has not been studied in details so far. Here, we studied the spectral weight transfer in the nematic phase of FeSe${}_{0.9}$S${}_{0.1}$ using angle-resolved photoemission spectroscopy and in-situ detwinning technique. There are two elliptical electron pockets overlapping with each other orthogonally at the Brillouin zone corner. We found that, upon cooling, one electron pocket loses spectral weight and fades away, while the other electron pocket gains spectral weight and becomes pronounced. Our results show that the symmetry breaking of electronic state is manifested by not only the anisotropic band dispersion but also the band-selective modulation of spectral weight. Our observation completes our understanding of the nematic electronic state, and put strong constraints on the theoretical models. It further provide crucial clues to understand the gap anisotropy and orbital-selective pairing in iron-selenide superconductors.

10 pages, 5 figures

References in corpus (8)

• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Theory of Electron Nematic Order in LaOFeAs
• The Structural Phase Transition in FeSe (Fe1+dSe)
• Lifting of xz/yz orbital degeneracy at the structural transition in detwinned FeSe
• Orbital Order and Spontaneous Orthorhombicity in Iron Pnictides
• Observation of two distinct $d_{xz}/d_{yz}$ band splittings in FeSe
• Momentum Dependence of the Nematic Order Parameter in Iron-Based Superconductors

Cited by in corpus (7)

• Electronic nematic states tuned by isoelectronic substitution in bulk FeSe1-xSx
• Non-local $d_{xy}$ nematicity and the missing electron pocket in FeSe
• FeSe and the missing electron pocket problem
• Anisotropic quasiparticle coherence in nematic BaFe${}_2$As${}_2$ studied with strain-dependent ARPES
• Unconventional localization of electrons inside of a nematic electronic phase
• Nematic spectral signatures of the Hund's metal
• Specific Heat and the gap structure of a Nematic Superconductor, application to FeSe