Evolution of spin excitations from bulk to monolayer FeSe
Artikel i vetenskaplig tidskrift, 2021

In ultrathin films of FeSe grown on SrTiO (FeSe/STO), the superconducting transition temperature T 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.

Författare

Jonathan Pelliciari

Brookhaven National Laboratory

Massachusetts Institute of Technology (MIT)

Seher Karakuzu

Oak Ridge National Laboratory

Qi Song

Fudan University

Riccardo Arpaia

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Politecnico di Milano

Abhishek Nag

Diamond Light Source

Matteo Rossi

Politecnico di Milano

Jiemin Li

Diamond Light Source

Tianlun Yu

Fudan University

Xiaoyang Chen

Fudan University

Rui Peng

Fudan University

M. Garcia-Fernandez

Diamond Light Source

Andrew C. Walters

Diamond Light Source

Q. Wang

Fudan University

Jun Zhao

Fudan University

Giacomo Ghiringhelli

Politecnico di Milano

Donglai Feng

Fudan University

Thomas A. Maier

Oak Ridge National Laboratory

Ke Jin Zhou

Diamond Light Source

Steven Johnston

University of Tennessee

Riccardo Comin

Massachusetts Institute of Technology (MIT)

Nature Communications

2041-1723 (ISSN)

Vol. 12 1 3122

Utvecklingen av nano laddning ordning i supraledande YBCO nanostrukturer

Vetenskapsrådet (VR) (2017-00382), 2017-07-01 -- 2020-06-30.

Ämneskategorier

Annan fysik

Teoretisk kemi

Den kondenserade materiens fysik

DOI

10.1038/s41467-021-23317-3

PubMed

34035254

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Senast uppdaterat

2021-06-08