Magnetic modes in Sr2IrO4 hint at exotic superconductivity

August 27, 2012

Researchers from Argonne’s Materials Science Division and the Advanced Photon Source used resonant inelastic x-ray scattering to reveal novel magnetic excitations in single crystals of the 5d transition metal oxide Sr2IrO4. In such 5d metal systems, collective excitations of electron spin and orbital degrees of freedom—fingerprints of the materials’ electronic structure—are inextricably coupled. The excitations discovered and modeled in this study have distinct characteristics found also in high Tc superconducting cuprates, fueling theoretical speculation that appropriate doping of electronic carriers into Sr2IrO4 could lead to a new class of unconventional superconductors.

Reference: J. Kim, D. Casa, M. H. Upton, T. Gog, Y-J. Kim, J. F. Mitchell, M. van Veenendaal, M. Daghofer, J. van den Brink, G. Khaliullin and B. J. Kim, “Magnetic excitation spectra of Sr2IrO4 probed by resonant inelastic x-ray scattering: Establishing links to cuprate superconductors,” Phys. Rev. Lett. 108, 177003 (2012) – Published 23 April 2012.