Insulating ferromagnetism in La4Ba2Cu2O10: an Ab initio wannier function analysis.
نویسندگان
چکیده
Microscopic mechanisms of the puzzling insulating ferromagnetism of half-filled La4Ba2Cu2O10 are elucidated with energy-resolved Wannier states. The dominant magnetic coupling, revealed through evaluated parameters (t, U, and J), turns out to be the intersite direct exchange, a currently ignored mechanism that overwhelms the antiferromagnetic superexchange. By contrast, the isostructural Nd4Ba2Cu2O10 develops the observed antiferromagnetic order via its characteristics of a 1D chain. Surprisingly, the in-plane order of both cases is not controlled by coupling between nearest neighbors. An intriguing pressure-induced ferromagnetic to antiferromagnetic transition is predicted.
منابع مشابه
Bonding and Electronic Properties of Ice at High Pressure
The properties of water ice at megabar pressure are characterized with ab initio computer simulations. The focus lies on the metallic Cmcm phase and its insulating distorted analogue with Pnma symmetry. Both phases were recently predicted to occur at 15.5 and 12.5 Mbar respectively [Phys. Rev. Lett. 105 (2010) 195701]. The Fermi surface of the Cmcm phase is analyzed and possibility of Fermi nes...
متن کاملElectronic structure and magnetism of Fe1ÀxPdx alloys
An ab initio linearized augmented plane-wave method has been employed to calculate the electronic and magnetic structures of both face-centered-cubic and body-centered-cubic Fe12xPdx alloys with x50.25, 0.50, and 0.75, respectively. Decreasing the Pd content in Fe12xPdx alloy from x51, the magnetic ordering of fcc Fe12xPdx changes from paramagnetism to ferromagnetism, ferrimagnetism, and finall...
متن کاملA Wannier function based ab initio Hartree-Fock approach extended to polymers: applications to the LiH chain and trans-polyacetylene
A recently proposed ab initio Hartree-Fock approach aimed at directly obtaining the Wannier functions of a crystalline insulator is applied to polymers. The systems considered are the LiH chain and trans-polyacetylene. In addition to being the first application of our approach to one-dimensional systems, this work also demonstrates its applicability to covalent systems. Both minimal as well as ...
متن کاملA Wannier-function-based ab initio Hartree-Fock study of polyethylene
In the present letter, we report the extension of our Wannier-function-based ab initio Hartree-Fock approach—meant originally for three-dimensional crystalline insulators—to deal with quasi-one-dimensional periodic systems such as polymers. The system studied is all-transoid polyethylene, and results on optimized lattice parameters, cohesive energy and the band structure utilizing 6-31G** basis...
متن کاملA Hartree-Fock ab initio band-structure calculation employing Wannier-type orbitals
An ab initio Wannier-function-based approach to electronic groundstate calculations for crystalline solids is outlined. In the framework of the linear combination of atomic orbitals method the infinite character of the solid is rigorously taken into account. The Hartree-Fock groundstate energy, cohesive energy, lattice constant and bulk modulus are calculated in a fully ab initio manner as it i...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 89 16 شماره
صفحات -
تاریخ انتشار 2002