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We present CoTe2 as a new type-II Dirac semimetal supporting Lorentz symmetry violating Dirac fermions in the vicinity of the Fermi energy. By combining first principle ab-initio calculations with experimental angle-resolved photo-emission spectroscopy results, we show the CoTe2 hosts a pair of type-II Dirac fermions around 90 meV above the Fermi energy. In addition to the bulk Dirac fermions, we find several topological band inversions in bulk CoTe2, which gives rise to a ladder of spin-polarized surface states over a wide range of energies. In contrast to the surface states which typically display Rashba-type in-plane spin splitting, we find that CoTe2 hosts novel out-of-plane spin polarization as well. Our work establishes CoTe2 as a potential candidate for the exploration of Dirac fermiology and applications in spintronic devices, infrared plasmonics, and ultrafast optoelectronics., Comment: 9 pages,7 figures, Accepted in Phys. Rev. B

Introduction:- Orofacial granulomatosis (OFG) is a disease entity with recurrent or persistent edema within the orofacial region. It frequently manifests as persistent and/or recurrent upper and/or lower labial lip and gingival enlargement. Histological features are non-necrotizing granulomas form in the affected tissues in the absence of any recognized systemic disease. The denite etiology of OFG is unidentied.1 Numerous theory have been recommended, including infection, genetic predisposition, and allergy.2-6 This report is a remarkable case ofCase report:- orofacial granulomatosis which presented as a recurrent severe generalized gingival enlargement in a eleven year-old child. There was no family history and no data of an underlying allergic or systemic cause. Oral prophylaxis showed mild alleviation of symptoms. Diagnosis ofConclusion: - orofacial granulomatosis is often difcult. OFG is cured by appropriate treatment.

Flat bands in twisted moire superlattices support a variety of topological and strongly correlated phenomena along with easily tunable electrical and optical properties. Here, we demonstrate the existence of tunable, long-lived, and flat intraband and interband terahertz plasmons in twisted double bilayer graphene. We show that the interband plasmons originate from the presence of a Van Hove singularity in the joint density of states and a finite Berry connection between the pair of bands involved. We find that the gapped interband plasmon mode has a universal dispersion, and the plasmon gap is specified by the location of the Van Hove singularity in the joint density of states. Metallic moire systems support an additional intraband plasmon mode which becomes flat in the large momentum limit because of the influence of the interband correlations. We demonstrate that the undamped and flat plasmon modes in moire systems are highly tunable and can be controlled by varying the vertical electric field and electron doping, and they persist over a wide range of twist angles., 4 figures, 9 pages