Rethinking the Orbital Ordering Transition: Using Coherent Soft X-ray Scattering to Study Dynamics in the CMR Manganites

The colossal magnetoresistance (CMR) phenomenon has baffled physicists since its discovery over a decade ago. Central to the puzzle is the short-range orbital ordering that arises in certain hole concentrations of the manganese oxides, even for low temperatures. We have used a Coherent Soft X-ray Scattering (CSXS) technique to resonantly enhance the orbital ordering contrast and measure speckle patterns from the domain structure of the self-assembling Mn d-orbitals. Our dynamics measurements suggest that the orbital domains remain static through the orbital ordering transition temperature -- challenging the previous belief of a mediation through slow, glass-like characteristics. Our experiments force us to rethink the role and nature of the orbitally-ordered state in the manganites, intrinsic to CMR.