Evolution of spin excitations from bulk to monolayer FeSe

@article{ WOS:000658774200001,
Author = {Pelliciari, Jonathan and Karakuzu, Seher and Song, Qi and Arpaia,
   Riccardo and Nag, Abhishek and Rossi, Matteo and Li, Jiemin and Yu,
   Tianlun and Chen, Xiaoyang and Peng, Rui and Garcia-Fernandez, Mirian
   and Walters, Andrew C. and Wang, Qisi and Zhao, Jun and Ghiringhelli,
   Giacomo and Feng, Donglai and Maier, Thomas A. and Zhou, Ke-Jin and
   Johnston, Steven and Comin, Riccardo},
Title = {{Evolution of spin excitations from bulk to monolayer FeSe}},
Journal = {{NATURE COMMUNICATIONS}},
Year = {{2021}},
Volume = {{12}},
Number = {{1}},
Month = {{MAY 25}},
Abstract = {{In ultrathin films of FeSe grown on SrTiO3 (FeSe/STO), the
   superconducting transition temperature T-c is increased by almost an
   order of magnitude, raising questions on the pairing mechanism. As in
   other superconductors, antiferromagnetic spin fluctuations have been
   proposed to mediate SC making it essential to study the evolution of the
   spin dynamics of FeSe from the bulk to the ultrathin limit. Here, we
   investigate the spin excitations in bulk and monolayer FeSe/STO using
   resonant inelastic x-ray scattering (RIXS) and quantum Monte Carlo (QMC)
   calculations. Despite the absence of long-range magnetic order, bulk
   FeSe displays dispersive magnetic excitations reminiscent of other
   Fe-pnictides. Conversely, the spin excitations in FeSe/STO are gapped,
   dispersionless, and significantly hardened relative to its bulk
   counterpart. By comparing our RIXS results with simulations of a bilayer
   Hubbard model, we connect the evolution of the spin excitations to the
   Fermiology of the two systems revealing a remarkable reconfiguration of
   spin excitations in FeSe/STO, essential to understand the role of spin
   fluctuations in the pairing mechanism. Here, Pelliciari et al. present
   resonant inelastic X-ray scattering on monolayer samples of
   unconventional superconductor FeSe, finding evidence for gapped and
   dispersionless spin excitations. These experiments are very difficult
   due to the extremely small scattering volume of the FeSe monolayer.}},
DOI = {{10.1038/s41467-021-23317-3}},
Article-Number = {{3122}},
ISSN = {{2041-1723}},
ResearcherID-Numbers = {{Zhao, Jun/A-2492-2010
   Wang, Qisi/F-9613-2013
   Maier, Thomas A/F-6759-2012
   }},
ORCID-Numbers = {{Zhao, Jun/0000-0002-0421-8934
   Wang, Qisi/0000-0002-8741-7559
   Maier, Thomas A/0000-0002-1424-9996
   Garcia Fernandez, Mirian/0000-0002-6982-9066
   Nag, Abhishek/0000-0002-1394-5105
   Rossi, Matteo/0000-0002-4254-0713
   Arpaia, Riccardo/0000-0003-4687-2376}},
Unique-ID = {{WOS:000658774200001}},
}