Effects of uniaxial strain in LaMnO3 - art. no. 114103

The effects of uniaxial strain on the structural. orbital, optical, and mag netic properties of LaMnO3 are calculated using realistic expressions for e lastic energies, along with a tight-binding parametrization of the band the ory and electron-phonon coupling. Tensile uniaxial strain of the order of 2 % (i.e., of the order of magnitude of those induced in thin films by lattic e mismatch with substrates) is found to change the magnetic ground state, c ausing dramatic changes in the band structure and optical conductivity spec trum. Related issues, including reasons why the observed (pi pi0) orbital o rdering is favored over a (pi pi pi) periodicity and why the uniform tetrag onal distortion mode is softer in insulating than in doped compounds, are d iscussed.