Yazar "Okan, S. Erol" seçeneğine göre listele

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    Anderson localization in optical lattices with speckle disorder
    (Amer Physical Soc, 2011) Sucu, Serpil; Aktas, Saban; Okan, S. Erol; Akdeniz, Zehra; Vignolo, Patrizia
    We study the localization properties of noninteracting waves propagating in a speckle-like potential superposed on a one-dimensional lattice. Using a combined decimation-renormalization procedure, we estimate the localization length for a tight-binding Hamiltonian where site energies are square-sinc-correlated random variables. By decreasing the width of the correlation function, the disorder patterns approach a delta-correlated disorder, and the localization length becomes almost energy independent in the strong disorder limit. We show that this regime can be reached for a size of the speckle grains on the order of (lower than) four lattice steps.
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    Characterization of dinaphthosulfoxide molecule
    (Elsevier Science Bv, 2015) Ulucam, Guhergul; Okan, S. Erol; Aktas, Saban; Ogretmen, Gul Penbe
    Dinaphthosulfoxide has been synthesized, and confirmed by the experimental methods. The geometrical optimization of the two isomers of the molecule in their ground state was studied using density functional theory. Then, NMR and IR spectra were calculated for the optimized configurations. Analyzing the hydroxyl features in the NMR data and that of sulfoxide in IR spectra, the experimental observables are found to be in agreement with the properties of the syn isomer. (C) 2015 Elsevier B.V. All rights reserved.
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    Energy levels of GaAs/AlxGa1-xAs/AlAs spherical quantum dot with an impurity
    (Elsevier Science Bv, 2016) Boz, Figen Karaca; Nisanci, Beyza; Aktas, Saban; Okan, S. Erol
    We have calculated the energy levels and the radial probability distributions of an electron with an impurity in a spherical quantum dot which is layered as GaAs/AlxGa1-xAs/AlAs. The numerical method used is the fourth-order Runge-Kutta method in the framework of the effective mass approximation. The variation of the energy levels have been calculated as functions of the radius of the GaAs sphere and the thickness of AlxGa1-xAs spherical layer considering effective mass and dielectric constant mismatches. The results have presented the importance of the geometry on the electronic properties of the spherical GaAs/AlxGa1-xAs/AlAs quantum dot. (C) 2016 Elsevier B.V. All rights reserved.
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    Synthesis and characterization of new N-heterocyclic carbene ligands: 1,3-Bis(acetamide)imidazol-3-ium bromide and 3-(acetamide)-1-(3-aminopropy1)-1H-imidazol-3-ium bromide
    (Elsevier, 2017) Turkyilmaz, Murat; Ulucam, Guhergul; Aktas, Saban; Okan, S. Erol
    Two new pincer type N-heterocyclic carbene ligands were synthesized. The compounds were characterized by FTIR, NMR (H-1, C-13) GC-MS and elemental analyses. They were also both modelled by DFT calculations as the crystal structure of 1,3-bis(acetamide)imidazol-3-ium bromide was determined by XRD which is an orthorhombic system with space group P2(1)2(1)2. The structural analyses in gas phase were realized by comparing the experimental NMR and IR spectra with those of the theoretical calculations. In vitro biological activities of the molecules were determined and found that one of them exhibits significant cytotoxic activity. (C) 2017 Elsevier B.V. All rights reserved.
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    Theoretical suggestions of resonant tunneling diodes and laser field effects on their current-voltage characteristics
    (Academic Press Ltd- Elsevier Science Ltd, 2019) Okan, S. Erol; Boz, Figen Karaca; Aktas, Saban
    Several resonance-tunneling diodes are modelled for a fixed resonance energy. The theoretically suggested diodes are classified according to their local potentials differed by the doping concentrations. The electronic properties of the diodes are explored in the framework of numerical calculations. In addition, the laser field effects on the latter properties are reported. They show that the laser field application enriches the functionality of these devices in applications.