Evolution of spin excitations from bulk to monolayer FeSe

@ARTICLE{Pelliciari2021,
	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 García-Fernández, 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},
	year = {2021},
	journal = {Nature Communications},
	volume = {12},
	number = {1},
	doi = {10.1038/s41467-021-23317-3},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85106908570&doi=10.1038%2fs41467-021-23317-3&partnerID=40&md5=c3747bfa9576b2786e9fb132fab5cdd6},
	abstract = {In ultrathin films of FeSe grown on SrTiO3 (FeSe/STO), the superconducting transition temperature Tc 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. © 2021, The Author(s).},
	correspondence_address = {J. Pelliciari; Department of Physics, Massachusetts Institute of Technology, Cambridge, United States; email: pelliciari@bnl.gov; R. Comin; Department of Physics, Massachusetts Institute of Technology, Cambridge, United States; email: rcomin@mit.edu},
	type = {Article},
	publication_stage = {Final},
	source = {Scopus},
	note = {All Open Access, Gold Open Access, Green Open Access}
}