Spin-orbital order in the undoped manganite LaMnO3 at finite temperature

Spin and orbital Ti magnetism at LaMnO3/SrTiO3 interfaces.

In systems with strong electron-lattice coupling, such as manganites, orbital degeneracy is lifted, causing a null expectation value of the orbital magnetic moment. Magnetic structure is thus determined by spin-spin superexchange. In titanates, however, with much smaller Jahn-Teller distortions, orbital degeneracy might allow non-zero values of the orbital magnetic moment, and novel forms of fe...

Origin of colossal magnetoresistance in LaMnO3 manganite.

Phase separation is a crucial ingredient of the physics of manganites; however, the role of mixed phases in the development of the colossal magnetoresistance (CMR) phenomenon still needs to be clarified. We report the realization of CMR in a single-valent LaMnO3 manganite. We found that the insulator-to-metal transition at 32 GPa is well described using the percolation theory. Pressure induces ...

Orbital Excitations in LaMnO3

We study the recently observed orbital excitations, orbitons, and treat electron-electron correlations and lattice dynamics on an equal footing. It is shown that the orbiton energy and dispersion are determined by both correlations and lattice vibrations. The electron-phonon coupling causes satellite structures in the orbiton spectral function and the elementary excitations of the system are mi...

Title Spin and orbital excitations in undoped manganites

Large magnetoresistance in a manganite spin tunnel junction using LaMnO3 as the insulating barrier

A spin tunnel junction based on manganites, with La1−xSrxMnO3 LSMO as ferromagnetic metallic electrodes and the undoped parent compound LaMnO3 LMO as insulating barrier, is here theoretically discussed using double-exchange model Hamiltonians and numerical techniques. For an even number of LMO layers, the ground state is shown to have antiparallel LSMO magnetic moments. This highly resistive, b...