Buckling-induced Zener polaron instability in half-doped manganites
نویسندگان
چکیده
By calculating the electronic, orbital, magnetic, and lattice structure of half-doped manganites we establish the central role of oxygen buckling caused by the tilting of the MnO6 octahedra, which is, in essence, a steric effect. The buckling itself does not change the Mn-Mn bonds. Instead, it drives the system toward an instability where these bonds can dimerize. In the presence of electron-electron interactions, this instability can fully develop, and beyond a critical buckling a Zener polaron ground state with dimerized spins, lattice, and orbitals forms spontaneously, resulting in a multiferroic state.
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