Low-Energy Wannier States (WS) Of Real Materials

Low-energy Wannier states (WS) of real materials. Top: Gapless excitations in the charge density wave phase of TaSe2 is explained with the unique geometric effects derived naturally from the phase interference of the WS. The hyrdization of 'ag and eg' symmetry essential to the understanding is clearly observed. (Phys. Rev. Lett. 96, 026406 (2006)). Bottom: Unexpectedly strong spin-dependence of resonant inelastic x-ray spectrum of LaMnO3 is explained by the strong charge transfer nature of LaMnO3, which is directly observable from the large hybridization with O-p states in the WS. Based on further novel WS analysis, origin of orbital ordering of MnF3 and LaMnO3 is, surprisingly, mainly electron-electron interaction, rather than the electron-phone coupling (Jahn-Teller effects). (Phys. Rev. Lett. 94, 047203 (2005) & cond-mat/0509075).

Image courtesy: Dr. Wei Ku, Brookhaven National Lab.