High-T_c d⁰ ferromagnetism in a doped Mott insulator: the case of hydrogenated epitaxial graphene on SiC(0001)

2015/05/26 by Pengcheng Chen, Chen, Pengcheng, Yuanchang Li +3
Computer Science · Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Graphene research and applications #Magnetic Field Sensors Techniques #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Parallel Computing and Optimization Techniques #cond-mat.mes-hall

paper · pdf · doi:10.48550/arxiv.1505.06823

13 pages, 3 figures

arxiv created 2015/05/26 · openalex publication_date 2015/05/26 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We show that the d⁰ ferromagnetism with high Curie temperature (T_c) can be achieved in the electron doped hydrogenated epitaxial graphene on some certain SiC substrates through first-principles calculations. The pristine systems are found to be a Mott insulator independent of SiC polytypes (2H, 4H or 6H) which, however, play a significant role in the modulation of magnetic interaction. Carrier doping enhances the ferromagnetic coupling due to the double exchange mechanism and thus realizes the phase transition from antiferromagnetism to ferromagnetism. A T_c of around 400 K is predicted on the 2H-SiC. We employ a non-degenerate Hubbard model to demonstrate how the SiC affects the interfacial magnetism in intra-atomic Coulomb repulsion and intersite hopping interactions.

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