The electronic structures of pristine graphene can be qualitatively described by tight-binding method. Tight-binding model is a simple method to understand the contributions of each atomic state. The method is helpful to investigate how chemical bonding, atomic arrangement, and structural symmetry reflect to the electronic structure of a system. Structural stability of monolayer graphene with...
The damping of spin waves in high-Tc cuprate superconductors was analytically calculated using the spin polaron formulation in the finite temperature Green’s function scheme. This representation describes holes as spinless fermions and spins as normal bosons which are characterized by hard core bosonic operators obtained using the Holstein-Primakoff transformation. The interaction between the...
The access to clean and potable water is an important challenge especially in Southeast Asian countries that are surrounded by bodies of water. Water contaminants such as dye effluents pose health hazards even in trace amounts and need to be accurately detected and quantified. Among various analytical techniques, Raman spectroscopy is recently becoming popular as a tool for the detection of...
We simulate the optimized fixed-point quantum search (OFPQS) algorithm with first- and second-nearest neighbor interactions in a 4-qubit Ising spin system using a nonrefocusing technique. In order to perform a single qubit gate, we utilize the coupling interactions to control the neighboring spins. The phase-marking scheme of the OFPQS is implemented using a single rotation about the...
Strain can change the physical and electrical properties of semiconductors. While strain can induce defects on semiconductors, its impacts are not always negative. Strain has been incorporated into semiconductor heterostructures to produce long wavelength (~1.55 µm) gallium arsenide (GaAs) based lasers. The changes that strain can make on semiconductor electrical properties in particular allow...
In this work, electronic and transport properties of a pristine sawtooth penta-graphene nanoribbon (SSPGNR) and sawtooth penta-graphene nanoribbons doping with Silic, Nitrogen, Phosphor (Si-SSPGNR, N-SSPGNR, P-SSPGNR) are studied systematically by density-functional theory in combination with the non-equilibrium Green’s function formalism. Pristine sample and three doped samples in a similar...
A recent study on FeSe thin films grown on different substrates revealed that films on CaF$_2$ substrate has the maximum $\textit{T$_c$}$ ~15 K. However, the monolayer FeSe grown on SrTiO$_3$ (STO) substrate generated much research interest when superconductivity was observed at $\textit{T$_c$}$ above 100 K by means of $\textit{in situ}$ four-point probe electrical transport measurements....
Doping and anion height are found to drastically affect the electronic structures of superconductors [1-2]. In this study, we investigated the composition-dependence of the electronic properties of the newly discovered intercalated TlFe$_{2}$Se$_{2}$ superconductor using density functional theory. We calculated the electronic structures of Tl$_{x}$Fe$_{2}$Se$_{2}$ with various Tl...
We deposit films from a bulk Bi-2212 target via femtosecond pulsed laser deposition. Smooth as-deposited films with large substrate coverage were grown on Si (100). The annealed films reveal crystallization in more than one direction. The XRD spectrum confirms that the annealed film is polycrystalline with some peaks that may have come from dissociated BSCCO compounds. Further testing will be...
Electrophoretic deposition of YBa2Cu3O7–δ is a promising non-vacuum method of film deposition due to its simplicity and scalability. In order to produce high quality films using this technique, it is necessary for the working suspension to be stable for long periods of time. In this study, we look at the interaction of YBCO and PbO2 particles when suspended in acetone. We determine if PbO2 is...
We investigate finite temperature electron conductivity in a hybrid system consisting of spatially separated two-dimensional layers of graphene and condensed indirect exciton gas coupled via the Coulomb interaction. We calculate the energy dependent relaxation time of the electrons in the graphene layer accompanied by the emission and absorption of a single Bogoliubov excitation (bogolon). We...
We consider a model of DNA toroidal condensate that corresponds to a twisted bundle arrangement and compare it to other models of the chain conformation inside the condensate. The latter models correspond to those of a spool-like folding and a constant curvature bending. The ground states of the condensate in different models are obtained by minimizing a total energy given by the sum of the...
