Plasmonic excitations and charge structure factor in armchair boron nitride nanotubes

In this paper we investigated theoretically both dynamical and static charge susceptibilities of armchair Boron-Nitride nanotube(BNNT). Using the imaginary part of the dynamical charge susceptibility function, one can find the plasmonic modes of the system. For this purpose we implement Green's function approach in the context of the tight-binding model hamiltonian. According to linear response theory the charge response function will be obtained via calculating the correlation function of charge density-density operators. Also we present the static charge structure factor which can be a criterion for charge ordering of the system. Especially the effect of gap parameter and chemical potential on the plasmon modes and static charge structure factor of armchair BNNT are investigated. Our results show that the chemical potential changes the number of plasmon modes and their positions. Furthermore chemical potential and gap parameter affect on the static charge susceptibility and consequently charge ordering of the BNNT is changed.