We perform X-ray and neutron scattering/spectroscopy experiments at large-scale facilities like synchrotrons and neutron sources to study the static and dynamic properties of crystal lattices, electrons, spins and their interactions in condensed matter systems. We also perform in-house X-ray diffraction and transport measurements.

Resonant Inelastic X-ray Scattering (RIXS)

RIXS employs X-rays that are tuned close to an absorption edge of the sample’s elements. It thus involves an intermediate transition from core levels to the unoccupied valence states. The resonance transition greatly enhances the sensitivity of RIXS to electronic correlations. In the presence of strong core-hole spin-orbit coupling, RIXS allows spin-flip (magnetic) scattering enabling the detection of magnetic correlations. In a RIXS process, the changes of photons’ energy, momentum, and polarization are transferred to the sample generating various elementary excitations such as phonon, magnon, charge excitations, dd-excitations, and plasmon. By measuring the changes of scattered photons, we can determine the dispersion relation of the generated excitations [1]. RIXS has been rapidly developing over the past decades. For soft-RIXS, the state-of-the-art energy resolution has reached ~40 meV with 1 keV x-rays.

References
[1] P. Ament et al., Rev. Mod. Phys. 83, 705 (2011).
[2] Q. Wang et al., Sci. Adv. 7, eabg7394 (2021).
[3] H. Lu et al., Science 373, 213 (2021).

Neutron Scattering

Neutron scattering can determine the crystalline and magnetic structures as well as their dynamics. This is becuase: (1) neutrons carry spin 1/2, and can thus interact with the dipole moments in the matter; (2) neutrons interact with the atoms via nuclear forces; (3) neutrons are charge neutral and thus have deep penetration into most materials; (4) the wavelengths and energies of neutrons used for our scattering experiments are comparable to the crystal lattice parameters and elementary excitations, respectively, leading to high momentum and energy resolutions. Due to the weak interaction with matter, neutron scattering is a bulk probe which can be combined with versatile sample environments like magnetic field, high pressure.

References
[4] N. S. Headings et al., Phys. Rev. Lett. 105, 247001 (2010).
[5] M. Mourigal et al., Nat. Phys. 9, 435 (2013).
[6] O. Delaire et al., Nat. Matter. 10, 614 (2011).
[7] I. Bustinduy et al., Rev. Sci. Instrum. 78, 043901 (2007).
[8] R. I. Bewley et al., Nucl. Instrum. Methods Phys. Res. A 637, 128 (2011).

Useful Links

[DAWN] [RIXSToolBox] [SpinW] [Sunny] [SpinWave] [McPhase] [McStas] [FullProf] [HORACE] [TobyFit] [MSLICE] [PACE] [MANTID] [DAVE] [MJOLNIR] [Data-Slicer] [ISOTROPY] [EDRIXS] [QUANTY] [CTM4XAS] [ICSD] [The Materials]