Subodha Mishra

Verwey transition in magnetite: Mean‐field solution of the three‐band model

The nature of the Verwey transition in magnetite (Fe3O4) within a three‐band spinless model Hamiltonian is examined. These bands, which arise from the minority‐spin t2g orbitals on the Fe(B) sublattice, are occupied by half an electron per Fe(B) atom. The Verwey order–disorder transition is studied as a function of the ratio of the intersite Coulomb repulsion U1 and the bandwidth W. It is found that the electrons are ordered beyond the critical value of U1/W≊0.25 in essential agreement with the results of the one‐band Cullen–Callen model. For larger values of U1/W, a Verwey‐like order is exhibited where the electrons occupy alternate (001) planes. The model predicts a transition from the metallic to the semiconducting state with the band gap increasing linearly with U1 beyond the transition point.

Spin polarization via electron tunneling through an indirect-gap semiconductor barrier

We study the spin dependent tunneling of electrons through a zinc-blende semiconductor with the indirect

Mean-field theory of charge ordering and phase transitions in the colossal-magnetoresistive manganites

X

Kronig–Penney model with the tail-cancellation method

(or

PHOTOINDUCED MAGNETISM IN THE FERROMAGNETIC SEMICONDUCTORS

\ensuremath{\Delta}

Schrödinger equation for the one-particle density matrix of thermal systems: an alternative formulation of Bose–Einstein condensation

) minimum serving as the tunneling barrier. The basic difference between tunneling through the

Magnetism, charge ordering, and metal–insulator transition in the lanthanum manganites (abstract)

\ensuremath{\Gamma}

One-dimensional photonic crystal: The Kronig-Penney model

vs the

Charge ordering via electron-electron interactions in the colossal-magnetoresistive manganites

X

ELECTRONIC STRUCTURE AND EXCHANGE INTERACTIONS IN THE MANGANESE-BASED PYROCHLORE OXIDES

barrier is the linear-