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Magnetic field effects on two-dimensional Kagome lattices

Takashi Kimura·Hiroyuki Tamura·Kenji Shiraishi·Hideaki Takayanagi
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Abstract

Magnetic field effects on single-particle energy bands (Hofstadter butterfly), Hall conductance, flat-band ferromagnetism, and magnetoresistance of two-dimensional Kagome lattices are studied. The flat-band ferromagnetism is shown to be broken as the flat-band has finite dispersion in the magnetic field. A metal-insulator transition induced by the magnetic field (giant negative magnetoresistance) is predicted. In the half-filled flat band, the ferromagnetic-paramagnetic transition and the metal-insulator one occur simultaneously at a magnetic field for strongly interacting electrons. All of the important magnetic fields effects should be observable in mesoscopic systems such as quantum dot superlattices.

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Takashi Kimura, Hiroyuki Tamura, Kenji Shiraishi, Hideaki Takayanagi. 2001-04-03. Magnetic field effects on two-dimensional Kagome lattices. https://doi.org/10.1103/physrevb.65.081307

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