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arXiv · 1202.5423

Electronic and magnetic properties in strongly correlated heterostructures

Suguru Ueda·Norio Kawakami·Manfred Sigrist
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Abstract

We present a theoretical study of a model heterostructure for a Mott-insulator sandwiched between two band insulators, such as SrTiO3/LaTiO3. Particular emphasis is given on the interplay between magnetism and inhomogeneous charge distributions. Our mean-field analysis of the generalized Hubbard model displays numerous ordered phases in the ground-state phase diagram. In particular, we find a canted antiferromagnetic state near the interface when antiferromagnetic-ordering exists inside the Mott insulator. A checkerboard charge-ordering proposed previously is also stabilized for large long-range Coulomb interactions. Regarding its origin we also point out the importance of interlayer spin-mediated interactions. It is further shown that such a strong spin-charge coupling gives rise to pronounced magnetic/charge order phase transitions in external magnetic fields: a firstorder metamagnetic transition and a reentrant charge-order transition with checkerboard pattern. The mechanisms stabilizing these intriguing phases are explored through a detailed analysis of the physical quantities with special focus on the spin-charge interplay.

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Suguru Ueda, Norio Kawakami, Manfred Sigrist. 2012-02-24. Electronic and magnetic properties in strongly correlated heterostructures. https://doi.org/10.1103/physrevb.85.235112

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