Flat band ferromagnetism without connectivity conditions in the flat band

Miklos Gulacsi; Gyorgy Kovacs; Zsolt Gulacsi

doi:10.1209/0295-5075/107/57005

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arXiv · 1411.6477

Flat band ferromagnetism without connectivity conditions in the flat band

Miklos Gulacsi·Gyorgy Kovacs·Zsolt Gulacsi

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Abstract

It is known that a system which exhibits a half filled lowest flat band and the localized one-particle Wannier states on the flat band satisfy the connectivity conditions, is always ferromagnetic. Without the connectivity conditions on the flat band, the system is non-magnetic. We show that this is not always true. The reason is connected to a peculiar behavior of the band situated just above the flat band.

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Miklos Gulacsi, Gyorgy Kovacs, Zsolt Gulacsi. 2014-11-24. Flat band ferromagnetism without connectivity conditions in the flat band. https://doi.org/10.1209/0295-5075%2F107%2F57005

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