Highly efficient beamline and spectrometer for inelastic soft X-ray scattering at high resolution

Lai, Chih‐Huang; Fung, H. S.; Wu, Wen Bin; Huang, Hung-Yi; Fu, Huang Wen; Lin, Shang‐Wei; Huang, S. W.; Chiu, C. C.; Wang, D. J.; Liang, Huang; Tseng, Tse-Chuan; Chung, S. C.; Chen, C. T.; Huang, D. J.

doi:10.1107/s1600577513030877

Cited by 53 publications

(43 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Defocusing and refocusing of the spectral components is achieved by angular dispersion from curved diffraction gratings. This approach has been recently demonstrated by Lai et al [5].…”

Section: Introductionmentioning

confidence: 93%

“…The above approach is general and applicable to any frequency domain. A particular version was proposed in the soft x-ray domain, for applications in resonant IXS spectroscopy at L-edges of 3d elements [4,5]. The dispersing elements in the soft x-ray and visible light domains are diffraction gratings.…”

Section: Theorymentioning

confidence: 99%

“…The dispersing elements in the soft x-ray and visible light domains are diffraction gratings. with diffraction gratings as dispersing elements [4,5].…”

Section: Theorymentioning

confidence: 99%

See 2 more Smart Citations

X-ray Echo Spectroscopy

Shvyd’ko

2016

Phys. Rev. Lett.

View full text Add to dashboard Cite

X-ray echo spectroscopy, a counterpart of neutron spin-echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a point-like x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x-rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02-meV ultra-high-resolution IXS applications (resolving power > 10 8 ) with broadband 5-13 meV dispersing systems are introduced featuring more than 10 3 signal enhancement. The technique is general, applicable in different photon frequency domains.

show abstract

“…Defocusing and refocusing of the spectral components is achieved by angular dispersion from curved diffraction gratings. This approach has been recently demonstrated by Lai et al [5].…”

Section: Introductionmentioning

confidence: 93%

Section: Theorymentioning

confidence: 99%

See 1 more Smart Citation

X-ray Echo Spectroscopy

Shvyd’ko

2016

Phys. Rev. Lett.

View full text Add to dashboard Cite

show abstract

“…Resolving these widths and the larger feature widths in the SrCuO 2 spectrum illustrates the femtosecond time scale on which local multiplet excitations can persist and interact meaningfully with the surrounding many-body environment. Several upcoming soft X-ray spectrometers are anticipated to reveal momentum dispersion in the critically important "thermal1" resolution regime (δE ∼ k B T near or below room temperature) [50][51][52][53][54][55], and superior energy resolution can also now be achieved with with hard X-rays [56,57] for certain specific cases such as the iridium L-edge.…”

Section: A New Regime Of Energy Resolutionmentioning

confidence: 99%

Extending resonant inelastic X-ray scattering to the extreme ultraviolet

et al. 2015

View full text Add to dashboard Cite

In resonant inelastic X-ray scattering (RIXS), core hole resonance modes are used to enhance coupling between photons and low energy electronic degrees of freedom. Resonating with shallow core holes accessed in the extreme ultraviolet (EUV) can provide greatly improved energy resolution at standard resolving power, but has been found to often yield qualitatively different spectra than similar measurements performed with higher energy X-rays. This paper uses experimental data and multiplet-based numerical simulations for the M-edges of Co-, Ni-, and Cu-based Mott insulators to review the properties that distinguish EUV RIXS from more commonly performed higher energy measurements. Key factors such as the origin of the strong EUV elastic line and advantages of EUV spectral functions over soft X-ray RIXS for identifying intrinsic excitation line shapes are discussed.

show abstract

“…Using the AGM-AGS spectrometer [37] at beamline TLS 05A1 of the National Synchrotron Radiation Research Center (NSRRC) in Taiwan, we measured RIXS on a polycrystalline LaCoO 3 and a single-crystal LaCoO 3 (001) samples [38] at incident photon energies set to specific energies about the L 3 (2p 3/2 → 3d) X-ray absorption edge of Co. The scattering angle defined as the angle between the incident and the scattered X-rays was 90…”

mentioning

confidence: 99%

Coulomb Correlations Intertwined with Spin and Orbital Excitations in LaCoO3

et al. 2017

View full text Add to dashboard Cite

We carried out temperature-dependent (20 -550 K) measurements of resonant inelastic X-ray scattering on LaCoO3 to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer multiplet calculations, we accurately quantified the renomalized crystal-field excitation energies and spin-state populations. We show that the screening of the on-site Coulomb interaction of 3d electrons is orbital selective and coupled to the spin-state crossover in LaCoO3. The results establish that the gradual spin-state crossover is associated with a relative change of Coulomb energy versus bandwidth, leading to a Mott-type insulator-to-metal transition.PACS numbers: 75.30. Wx, 71.70.Ch, 78.70.En The orbital degree of freedom of an electron characterizes the shape of the electron cloud and its wave function. It plays an essential role in the physics of phase transitions in solids via the coupling of charge, spin and lattice degrees of freedom, even in the presence of strong Coulomb interactions, for example, as in Mott insulators. The spatial redistribution of the electron cloud as a function of an external parameter such as temperature often manifests as co-operative phenomena leading to a metal-insulator transition [1], orbital ordering [2, 3], nematic transition [4,5], spin-state transition [6-10], etc. These results in exotic properties like superconductivity, quantum criticality, colossal magnetoresistance, etc. As the Coulomb interaction is a key to Mott physics [11][12][13][14], one fundamental question in correlated electron systems with orbital degrees of freedom is: how do the Coulomb correlations change dynamically through the rearrangement of the electronic distribution? This is usually beyond the scope of even multi-orbital model Hamiltonians in which the Coulomb interaction parameters are considered inflexible. An important theoretical advance in this direction is the role of orbital selective screening [15]. The effective Coulomb interaction for t 2g electrons was shown to be significantly reduced due to efficient e g electron screening, providing an improved understanding of LaMO 3 (M = 3d transition metals from Ti to Cu) series of perovskite oxides. This concept of the screened on-site Coulomb interaction has been developed recently using the constrained random-phase-approximation technique [16][17][18].In this Letter, we exploited resonant inelastic X-ray scattering (RIXS) to investigate spin-orbital excitations in LaCoO 3 and to measure its spin-state populations and the renormalized crystal-field excitations across the spinstate transition. an ideal candidate to examine the role of orbital selective screening of Coulomb interactions as a function of temperature. We found that the spin-state crossover is driven by the thermal excitation of high-spin (HS) states and accompanied by the reduction in effective Coulomb energy and an increase of covalency, culminating in an effective Coulomb-energy-vs-bandwidth type insulator-tometal transition.arXiv:1708.044...

show abstract

Highly efficient beamline and spectrometer for inelastic soft X-ray scattering at high resolution

Cited by 53 publications

References 22 publications

X-ray Echo Spectroscopy

X-ray Echo Spectroscopy

Extending resonant inelastic X-ray scattering to the extreme ultraviolet

Coulomb Correlations Intertwined with Spin and Orbital Excitations in LaCoO3

Contact Info

Product

Resources

About