What Is the Interplay among Spin, Charge, and Orbital Ordering in Transition-Metal Oxides?
These orderings produce dramatic changes in physical properties, such as resistivity and magnetoresistance, and can be tuned by small changes in composition and by application of a magnetic field. How and why do these superlattices form and what is the relation between the different orderings, including phase separation? 8. What Are the Elementary Excitations of Systems that Undergo Coupled Spin and Orbital Order? Some metal-oxide systems order their spins and orbital moments in a coordinated manner. Since the energy scales of the spin wave, orbital waves, and the coupling between them are all comparable, the elementary excitations will also be of mixed character. Soft xrays are ideal for probing these excitations because of their ability to couple directly to the orbital moments. 9. What Are the Roles of (Local) Phonons, Orbital Ordering, and Phase Separation in Colossal-Magnetoresistive (CMR) Materials? In the CMR materials the carriers interact so strongly with local orbital (L), sp
