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Orbital Ordering, New Phases, and Stripe Formation in Doped Layered Nickelates

Takashi Hotta·Elbio Dagotto
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Abstract

Ground-state properties of layered nickelates are investigated based on the orbital-degenerate Hubbard model coupled with lattice distortions, by using umerical techniques. The Néel state composed of spin S=1 ions is confirmed in the undoped limit x=0. At x=1/2, novel antiferromagnetic states, called CE- and E-type phases, are found by increasing the Hund's coupling. (3 x^2 - r^2 / 3 y^2 - r^2)-type orbital ordering is predicted to occur in a checkerboard-type charge-ordered state. At x=1/3, both Coulombic and phononic interactions are found to be important, since the former stabilizes the spin stripe, while the latter leads to the striped charge-order.

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Takashi Hotta, Elbio Dagotto. 2004-01-29. Orbital Ordering, New Phases, and Stripe Formation in Doped Layered Nickelates. https://doi.org/10.1103/physrevlett.92.227201

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