Next Generation Science with Inelastic X-ray Scattering Clement Burns Western Michigan University Thanks to: Yuri Shyvd’ko, Ercan Alp, Ayman Said (APS) Peter Abbamonte (UIUC) Zahid Hasan (Princeton)

Six Challenges for Physics National Research Council Review of Physics (2001) Developing quantum technologies Understanding complex systems Applying physics to biology Creating new materials Exploring the universe Unifying the forces of nature NRC for physics

Energy - Momentum Relationships

Focus with X-ray Mirrors Small Beam High flux for experiments IXS flux hungry technique >1016 P=photon/sec-0.1% bandwidth Small beam size (<4 x 40 mm2) High pressure work Nanomaterials New materials E.g., MgB2 Devices Surfaces Environmental But… start 2014                                            NSLS II 1014 photons 100 meV width at 10 keV, 1012 at 1 meV Don’t just do the same experiments http://www.esrf.eu/UsersAndScience/Publications /Highlights/2002/Imaging/IMA8/fig103 http://www.physics.umd.edu/mfuhrer/images/longNT.jpg

Science with 0.1 meV Resolution

Need for Higher Resolution DNA Liu, J. Chem. Phys. 123, 214909 2005 1.5 meV Sette Johnny von Neumann used to say, 'with four parameters I can fit an elephant and with five I can make him wiggle his trunk quote by Fermi Pilla et al, PRL 85, 2136 (2000) DNA Krisch PRE 73, 061909 2006 DHO Memory Fun.

Science at 0.1 meV 1 meV resolution does not mean one can study excitations with an energy of 1 meV Large background from elastic High resolution and good elastic rejection From Yuri Shvyd’ko

Reinstäder, Phys. Rev. Lett. 93, 108107 (2004) Possible Science Low energy excitations in polymers Related to wetting, adhesion.. Lipid membranes Mapping superconducting band gap with phonons Dynamics of glasses Lipids fat soluble molecules (includes cholesterol) Inoue, PRL 95, 056102 (2005) Reinstäder, Phys. Rev. Lett. 93, 108107 (2004)

0.1 meV Science BRISP Neutron Brillouin IUVS inelastic ultraviolet scattering, From Ruocco

Science with 1 meV Resolution

Some Ideas at 1 meV Extreme environments – low temperature, high field, ultrahigh pressure Small samples Down to nanoparticle size (High pressure) Surface phonons Grazing incidence requires small beam 10’ yields ~1.5 mm on sample Most current techniques require high vacuum Exotic excitations Orbitons Resonant scattering? Pulse probe technique – phonons in excited states Can also do scattering under other extreme environments – high field, low temperature

Extreme Environments High pressure High Temperature Levitated Liquids High pressure High Temperature High magnetic fields Low temperature Heating issues Sinn, Science 299, 2047 (2003)

Small Samples New materials – e.g., phonons in MgB2 Samples/regions in crystals - Pu Really small ? 100 nm? Smaller? Nanotubes? Wong et. al, Science 301, 1071 (2003)

Surface Phonon Scattering IXS can do both on same sample 2-d behavior important for devices as well as fundamental science Thin films (need to compare to e.g., He scattering) Buried interfaces? Study 2-d behavior liquids Murphy et. al, PRL 95, 256104 (2005)

Case for Medium Resolution It’s a “slam dunk” – as strong as the case for meV or sub meV

Science at Medium Resolution Electronic excitations Plasmons, excitons, spinons, holons, Mott gap, band transitions, superconducting gap…. Non-resonant scattering – easy comparison to (q,) Resonant scattering –site and state selective Soft x-ray edges at high energy Time evolution of systems Study highly correlated electron systems, Mott-Hubbard insulators, organic semiconductors, regular metals, …new systems everyday

Scattering Cross Section From Platzman and Isaacs, PRB 57, 11107 (1998) Non-resonant Scattering

Medium Resolution Work IXS Organic Molecular Crystal Spinon-holon Yang et al., PRL 98, 036404 (2007) Y. Cai, et al, Phys. Rev. Lett. 2006 June et al., PRL 137402 (2004) www.afrlhorizons.com/Briefs/Jun04/ML0319.html Kodituwakku et al, submitted to PRL

Medium Resolution RIXS Opportunities

Resonant Scattering Energies

Medium Resolution – Monochromator Improvements Tom Toellner, APS Four bounce High efficiency Wide energy range

Medium Resolution Spectrometer Detector Improvements Line detector Huotari et al., ESRF Shvyd’ko APS Improve counts Larger solid angle Improve resolution Reduces geometric effect Other energies? S. Huotari et al., Journal of Synchrotron Radiation 20, 467-472 (2005).

Why do we need NSLS-II? Smaller samples can be studied New materials, high pressure Many, many systems to look at Higher resolution - necessary for many cases…

Low Resolution Options Important! Dynamics on attosecond time scales From Peter Abbamonte

Low / Adjustable Resolution Dipole forbidden d-d excitations Information about Larson et al., PRL 99, 026401 (2007)

Observations No one cares how good the NSLS-II synchrotron is …. They care about the quality of science Many good ideas for IXS Throw out most of them Use strengths of NSLS-II Develop early – detectors, etc. Room for future ideas Adjustable resolution Support Sample orientation/alignment Characterization (other departments?)