Browsing by Author "Senger, R. T."
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Abinitio electron transport calculations of carbon based string structures
Tongay, S.; Senger, R. T.; Dag, S.; Çıracı, Salim (American Physical Society, 2004)The new stable structures of carbonbased strings and their unusual electronic transport properties were discussed. Total energy and electronic structure calculations using first principles pseudopotential plane wave method ... 
Atomic and electronic structure of carbon strings
Tongay, S.; Dag, S.; Durgun, Engin; Senger, R. T.; Çıracı, Salim (IOP Publishing Ltd., 2005)This paper presents an extensive study of various string and tubular structures formed by carbon atomic chains. Our study is based on firstprinciples pseudopotential plane wave and finitetemperature ab initio molecular ... 
Atomic chains of groupIV elements and IIIV and IIVI binary compounds studied by a firstprinciples pseudopotential method
Senger, R. T.; Tongay, S.; Durgun, Engin; Çıracı, Salim (American Physical Society, 2005)Using the firstprinciples plane wave pseudopotential method we have studied structural, electronic, and transport properties of atomic chains of groupIV elements and group IIIV and group IIVI binary compounds. Several ... 
Bilayer SnS2: tunable stacking sequence by charging and loading pressure
Bacaksiz, C.; Cahangirov, S.; Rubio, A.; Senger, R. T.; Peeters, F. M.; Sahin, H. (American Physical Society, 201603)Employing density functional theorybased methods, we investigate monolayer and bilayer structures of hexagonal SnS2, which is a recently synthesized monolayer metal dichalcogenide. Comparison of the 1H and 1T phases of ... 
Binding energies of excitons in IIVI compoundsemiconductor based quantum well structures
Senger, R. T.; Bajaj, K. K. (Wiley  V C H Verlag GmbH & Co., 2004)We present a brief description of the calculation of the variation of the binding energy of the heavyhole exciton as a function of well width in quantum well structures composed of IIVI compound semiconductors including ... 
Carbon string structures: Firstprinciples calculations of quantum conductance
Senger, R. T.; Tongay, S.; Dag, S.; Durgun, Engin; Çıracı, Salim (American Physical Society, 2005)Carbon forms various nanostructures based on the monatomic chains or strings which show transport properties of fundamental and technological interest. We have carried out firstprinciples quantum conductance calculations ... 
Chiral singlewall gold nanotubes
Senger, R. T.; Dag, S.; Çıracı, Salim (American Physical Society, 2004)The formation of freestanding and tipsuspended chiralwall (n,m) nanotubes, which were composed of helical atomic strands, from gold atoms was investigated using firstprinciples calculations, where (n,m) notation defines ... 
Determination of energyband offsets between GaN and AlN using excitonic luminescence transition in AlGaN alloys
Westmeyer, A. N.; Mahajan, S.; Bajaj, K. K.; Lin J. Y.; Jiang, H. X.; Koleske, D. D.; Senger, R. T. (American Institute of PhysicsA I P Publishing LLC, 2006)We report the determination of the energyband offsets between GaN and AlN using the linewidth (full width at half maximum) of an extremely sharp excitonic luminescence transition in Alx Ga1x N alloy with x=0.18 at 10 K. ... 
Dynamics of phononic dissipation at the atomic scale: Dependence on internal degrees of freedom
Sevinçli, H.; Mukhopadhyay, S.; Senger, R. T.; Çıracı, Salim (American Physical Society, 2007)Dynamics of dissipation local vibrations to the surrounding substrate is a key issue in friction between sliding surfaces as well as in boundary lubrication. We consider a model system consisting of an excited nanoparticle ... 
Energy and mass of 3D and 2D polarons in the overall range of the electronphonon coupling strength
Ercelebi, A.; Senger, R. T. (Institute of Physics Publishing Ltd., 1994)The groundstate characterization of the polaron problem is retrieved within the framework of a variational scheme proposed previously by Devreese et al for the bound polaron. The formulation is based on the standard ... 
Energytransfer rate in a doublequantumwell system due to Coulomb coupling
Senger, R. T.; Tanatar, Bilal (Elsevier, 2002)We study the energytransfer rate for electrons in a doublequantumwell structure, where the layers are coupled through screened Coulomb interactions. The energytransfer rate between the layers (similar to the Coulomb ... 
Firstprinciples calculations of spindependent conductance of graphene flakes
Şahin, H.; Senger, R. T. (The American Physical Society, 2008)Using ab initio densityfunctional theory and quantum transport calculations based on nonequilibrium Green's function formalism we study structural, electronic, and transport properties of hydrogenterminated short graphene ... 
Groundstate description of quasionedimensional polarons with arbitrary electronphonon coupling strength
Erçelebi, A.; Senger, R. T. (American Physical Society, 1996)We consider the interaction of a confined electron with bulk polaroptical phonons in a cylindrical quantum well wire with infinite boundary potential. Expressions for the polaron selfenergy and mass are derived within a ... 
Halfmetallic properties of atomic chains of carbontransitionmetal compounds
Dag, S.; Tongay, S.; Yildirim, T.; Durgun, Engin; Senger, R. T.; Fong, C. Y.; Çıracı, Salim (American Physical Society, 2005)We found that magnetic ground state of onedimensional atomic chains of carbontransitionmetal compounds exhibit halfmetallic properties. They are semiconductors for one spin direction, but show metallic properties for ... 
HartreeFock approximation of bipolaron state in quantum dots and wires
Senger, R. T.; Kozal, B.; Chatterjee, A.; Erçelebi, A. (Springer, 2010)The bipolaronic ground state of two electrons in a spherical quantum dot or a quantum wire with parabolic boundaries is studied in the strong electronphonon coupling regime. We introduce a variational wave function that ... 
Layerand straindependent optoelectronic properties of hexagonal AIN
Kecik, D.; Bacaksiz, C.; Senger, R. T.; Durgun, Engin (American Physical Society, 2015)Motivated by the recent synthesis of layered hexagonal aluminum nitride (hAlN), we investigate its layer and straindependent electronic and optical properties by using firstprinciples methods. Monolayer hAlN is a ... 
Magnetic field effects on an electron near an impenetrable dielectric surface
Saqqa, B.; Senger, R. T.; Erçelebi, A. (1996)The interaction of an extrinsic electron with the surface optical modes of a semiinfinite medium is retrieved under the effect of a weak magnetic field. It is observed that for an electron in a bound state near the surface, ... 
Monolayer honeycomb structures of groupIV elements and IIIV binary compounds: Firstprinciples calculations
Şahin, H.; Cahangirov, S.; Topsakal, M.; Bekaroglu, E.; Akturk, E.; Senger, R. T.; Çıracı, Salim (American Physical Society, 2009)Using firstprinciples planewave calculations, we investigate twodimensional (2D) honeycomb structure of groupIV elements and their binary compounds as well as the compounds of group IIIV elements. Based on structure ... 
Monte Carlo simulation of localization dynamics of excitons in ZnO and CdZnO quantum well structures
Makino, T.; Saito, K.; Ohtomo, A.; Kawasaki, M.; Senger, R. T.; Bajaj, K. K. (American Institute of Physics, 2006)Localization dynamics of excitons was studied for ZnOMgZnO and CdZnOMgZnO quantum wells (QWs). The experimental photoluminescence (PL) and absorption data were compared with the results of Monte Carlo simulation in which ... 
Nanospintronic properties of carboncobalt atomic chains
Durgun, Engin; Senger, R. T.; Mehrez, H.; Dag, S.; Çıracı, Salim (EDP Sciences, 2006)Periodic atom chains of carboncobalt compounds, (CnCo) ∞, comprise both conducting and insulating electronic properties simultaneously depending on the spin type of electrons, and hence are halfmetals. Their band gap and ...