Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2001-01-23
Physics
Condensed Matter
Strongly Correlated Electrons
9 pages with 7 embedded postscript figures and 2 tables
Scientific paper
10.1103/PhysRevB.64.064401
CaMnO3 is a simple bi-partite antiferromagnet(AF) which can be continuously electron-doped up to LaMnO3. Electrons enter the doubly degenerate E_g subshell with spins aligned to the S=3/2 core of Mn^4+ (T_2g^3)$. We take the Hubbard and Hund energies to be effectively infinite. Our model Hamiltonian has two E_g orbitals per Mn atom, nearest neighbor hopping, nearest neighbor exchange coupling of the S=3/2 cores, and electron-phonon coupling of Mn orbitals to adjacent oxygen atoms. We solve this model for light doping. Electrons are confined in local ferromagnetic (FM) regions (spin polarons) where there proceeds an interesting competition between spin polarization (spin polarons) which enlarges the polaron, and lattice polarization (Jahn-Teller polarons) which makes it smaller. A symmetric 7-atom ferromagnetic cluster (Mn_7^27+) is the stable result, with net spin S=2 relative to the undoped AF. The distorted oxygen positions around the electron are predicted. The model also predicts a critical doping x_c=0.045 where the polaronic insulator becomes unstable relative to a FM metal.
Allen Philip B.
Chen Yiing-Rei
No associations
LandOfFree
Spin versus Lattice Polaron: Prediction for Electron-Doped CaMnO3 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spin versus Lattice Polaron: Prediction for Electron-Doped CaMnO3, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spin versus Lattice Polaron: Prediction for Electron-Doped CaMnO3 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-604969