Electronic properties of Boron Nitride sheet and nanotube in the pre- sence of transverse magnetic field H. Rezania n , Z. Aghaiimanesh Department of Physics, Razi University, Kermanshah, Iran HIGHLIGHTS  Theoretical calculation of density of states and specific heat in the presence of magnetic field.  The investigation of specific heat versus temperature for different magnetic field and Hubbard parameter.  The investigation of density of states for various magnetic field and Hubbard parameter. article info Article history: Received 5 December 2014 Received in revised form 31 March 2015 Accepted 22 May 2015 PACS: 73.22. f 72.80.Vp 73.63. b 78.20. e Keywords: Boron-Nitride Hubbard model Specific heat abstract We study the effects of a transverse magnetic field on the electronic properties of both Boron-Nitride monolayer and zigzag nanotubes in the context of Hubbard model at the antiferromagnetic sector. In particular, the behavior of density of states and temperature dependence of specific heat have been investigated. Mean field approximation has been employed in order to obtain the electronic spectrum of the system. Our results show the band gap in the density of states broadens with an increase of Hubbard parameter. Whereas the band gap width decreases with magnetic field. Also specific heat of Boron Ni- tride sheet is found to be exponentially increasing behavior with temperature at low values of it and for all the magnetic field values. However specific heat reaches its maximum value at finite temperature and specific heat starts to decrease upon more increase of temperature. Furthermore the effect of magnetic field and Hubbard interaction on the density of states and specific heat of Boron Nitride nanotubes has been studied. & 2015 Elsevier B.V. All rights reserved. 1. Introduction Condensed matter physics in low dimension made up of carbon atoms could form special geometric structures such as a graphene sheet [1], a quasi-one dimensional carbon nanotube (CNT) and nanographite ribbon [2,3]. Briefly after the discovery of carbon nanotubes (CNTs) [3,4], and based on the similarities among gra- phite and other sp 2 -like bonded materials, the existence of Boron- Nitride nanotubes (BNNTs) was theoretically predicted [5,6] and experimentally realized in the following year [7]. BNNTs are structurally similar to carbon nanotubes, thus they exhibit extra- ordinary mechanical properties like CNTs [8,9]. In contrast to the CNTs, the electronic properties of BNNTs are nearly independent of the tube diameter, chirality and whether the nanotube is single walled, multi-walled or packed in bundles [5,6]. The theoretical calculations have predicted the band gap of BNNTs around E5 eV and can be eliminated by transverse electric fields through the giant DC stark effect [10]. Among these nanoscale systems that present interesting op- toelectronic properties, one can point to the systems with elec- tronic energy gap. It is well known that many-body effects play a crucial role in low-dimensional nanostructures [11,12]. The role of Coulomb interaction in graphene and related materials can be expected to be a significant factor in the appearance of magnetic ordering [13,14]. In other words, the electronic spectrum of tight binding model Hamiltonian on the honeycomb lattice can be modified via many body interactions such as coulomb repulsion [15]. From applications point of view, it is important to open up a gap in the spectrum by lowering the symmetry of the nearest neighbor tight binding Hamiltonian. For example the substrate can induce a sublattice symmetry breaking, e.g. by considering a dif- ference between two on-site energy sublattices. Boron nitride monolayers and nanotubes have such property. Therefore this Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/physe Physica E http://dx.doi.org/10.1016/j.physe.2015.05.022 1386-9477/& 2015 Elsevier B.V. All rights reserved. n Corresponding author. Fax: þ98 831 427 4556. E-mail address: rezania.hamed@gmail.com (H. Rezania). Physica E 73 (2015) 100–104 Downloaded from http://www.elearnica.ir