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Title: Charge Dynamics in Low Dimensional Prototype Correlated Systems: A View with High-Energy X-rays

Charge Dynamics in Low Dimensional Prototype Correlated Systems: A View with High-Energy X-rays The electronic structure of Mott systems continues to be an unsolved problem in physics despite more than half-century of intense research efforts. Well-developed momentum-resolved spectroscopies such as photoemission and neutron scattering cannot directly address problems associated with the full Mott gap as angle-resolved photoemission probes the occupied states and neutrons do not couple to the electron's charge directly. Our observation of dispersive particle- hole pair excitations across the charge gap (effective Mott gap) in several low dimensional prototype Mott insulators using high resolution resonant inelastic x-ray scattering suggests that the excitations across the gap are highly anisotropic and momentum dependent. The results indirectly provide some information about the momentum dependence of unoccupied states in these correlated systems. The x-ray scattering results are complementary to the electron scattering results by the possibility of studying the excitations in the high momentum transfer regimes (near the zone boundaries and comers). This is also demonstrated in case of studying plasmons near the wave vector regime where Landau damping starts to dominate. X-ray scattering also allows one to probe the symmetry characters of localized electrons and the excitations through the strong polarization dependence of scattering near a core resonance. The study of charge-orbital localization is more » demonstrated in case of manganese oxides. Given its deeply bulk-sensitive and weak-coupling nature and the ability to probe dispersive behavior of charge fluctuations over several Brillouin zones, inelastic x-ray scattering shows the promise to become an important experimental tool to study the electronic structure of complex quantum systems. « less
Authors:
Publication Date:
OSTI Identifier:OSTI ID: 799074
Report Number(s):SLAC-R-589
TRN: US0204803
DOE Contract Number:AC03-76SF00515
Resource Type:Technical Report
Resource Relation:Other Information: PBD: 20 Mar 2002
Research Org:Stanford Linear Accelerator Center, Menlo Park, CA (US)
Sponsoring Org:USDOE Office of Energy Research (ER) (US)
Country of Publication:United States
Language:English
Subject: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BRILLOUIN ZONES; ELECTRONIC STRUCTURE; LANDAU DAMPING; MANGANESE OXIDES; MOMENTUM TRANSFER; PHOTOEMISSION; PHYSICS; PLASMONS; POLARIZATION; RESONANCE; SCATTERING; SYMMETRY; VECTORS