Detecting the orbital character of the spin fluctuation in the iron-based superconductors with the resonant inelastic X-ray scattering spectroscopy

Department of Physics, Renmin University of China - Beijing 100872, PRC

Received: 16 August 2018
Accepted: 8 February 2019

Abstract

The orbital distribution of the spin fluctuation in the iron-based superconductors (IBSs) is the key information needed to understand the magnetism, superconductivity and electronic nematicity in these multi-orbital systems. In this work, we propose that the resonant inelastic X-ray scattering (RIXS) technique can be used to probe selectively the spin fluctuation on different Fe 3d orbitals. In particular, the spin fluctuation on the three t_2g orbitals, namely, the 3d_xz, 3d_yz and the 3d_xy orbital, can be selectively probed in the scattering geometry by aligning the direction of the outgoing photon in the y-, x- and z-direction. Such orbital-resolved information on the spin fluctuation is invaluable for the study of the orbital-selective physics in the IBSs and can greatly advance our understanding of the relation between orbital ordering and spin nematicity in the IBSs and the orbital-selective pairing mechanism in these multi-orbital systems.