Session G32: Focus Session: Orbital/Charge Order in Complex Oxides

8:00 AM–11:00 AM, Tuesday, March 14, 2006
Baltimore Convention Center - 329

Sponsoring Units: DMP GMAG
Chair: Ray Osborn, Argonne National Laboratory

Abstract ID: BAPS.2006.MAR.G32.2

Abstract: G32.00002 : Theoretical study of charge, spin, and orbital order in half-doped $La_{0.5}Ca_{0.5}MnO_3$.

8:12 AM–8:24 AM

Preview Abstract

Authors:

  Dmitri Volja
  Weiguo Yin
  Wei Ku
    (BNL)

Deep microscopic insights into the half-doped $La_{0.5}Ca_{0.5}MnO_3$ are obtained with a novel construction of many-body picture derived from LDA+U and Wannier state analysis. Experimentally observed zig-zag orbital order and CE-type magnetic structure is found to have only very weak charge disproportionation. The apparent contradiction between well-defined bridge (3+) and corner (4+) Mn sites and the weak charge disproportionation is resolved naturally with occupied Wannier states centered at 3+ sites extending to 4+ and O-sites (reflecting non-negligible charge-transfer nature of the system.) Contrary to current lore, electron-electron interaction is found crucial to the long-range order in ordering the orbital and the spin. Specific experimental means of verification (e.g.: measurement of pseudospin direction) are suggested.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2006.MAR.G32.2