Now showing items 207-225 of 225

    • Temperature dependent density profiles and collective oscillations of dipolar droplets 

      Aybar, Enes (Bilkent University, 2019-09)
      Dipolar droplets are a novel form of Bose gas that form in a regime where the mean field theory predicts collapse. In the literature, the beyond mean field e ects in the form of the Lee-Huang-Yang correction to the local ...
    • A theoretical model for the epitaxial growth of Si(100) surface 

      Dağ, Sefa (Bilkent University, 2000)
      In this thesis, we investigated atomic scale mechanisms of growth on the Si(lOO) surface. First principles quantum molecular dynamics calculations are performed, where self-consistent field electronic structure calculations ...
    • Theory of atomic scale friction 

      Buldum, Alper (Bilkent University, 1998)
      Friction is an old and important but at the same time very complex physical event. This thesis aims to develop an atomic scale theory of friction. VVe investigate various atomic processes and stick-slip motion by using ...
    • Thermoelectric efficiency in model nanowires 

      Badalov, Sabuhi (Bilkent University, 2013)
      Nowadays, the use of thermoelectric semiconductor devices are limited by their low efficiencies. Therefore, there is a huge amount of research effort to get high thermoelectric efficient materials with a fair production ...
    • Tight binding modeling of two dimensional and quasi-two dimensional materials 

      Singh, Deepak Kumar (Bilkent University, 2017-10)
      Since the advent of graphene, two-dimensional (2D) materials have consistently been studied owing to their exceptional electronic and optical properties. While graphene is completely two-dimensional in nature, its other ...
    • Time dependent study of quantum bistabiliity 

      Ecemiş, Mustafa Ihsan (Bilkent University, 1995)
      The analysis of quantum transport phenomena in small systems is a prominent topic of condensed matter physics due to its numerous technological applications. The current analytical theories are not adequate for ...
    • A time-dependent study of bistability in resonant tunneling structures 

      Keçecioğlu, Ersin (Bilkent University, 1997)
      A comjDutational time-dependent study of the bistability in resonant tunneling structures including the electron-electron interactions is presented. A new computational method for the investigation of many jDarticle ...
    • Titanium dioxide nanostructures for photocatalytic and photovoltaic applications 

      Çakır, Deniz (Bilkent University, 2008)
      In this thesis, TiO2 nanostructures and their photocatalytic and photovoltaic ap- plications have been investigated by using the ¯rst-principles calculations based on density functional theory. We have concentrated on ...
    • Topological aspects of charge transport in quantum many-body systems 

      Yahyavi, Mohammad (Bilkent University, 2019-02)
      Motivated by the recent proposals and developments of topological insulators and topological superconductors for their potential applications in electronic devices and quantum computing, we have theoretically studied ...
    • Tuning the exciton-plasmon coupling 

      Ateş, Simge (Bilkent University, 2012)
      Exciton-plasmon coupling has recently drawn much interest. In this work, FDTD simulations of exciton-plasmon coupling in plasmonic cavity structures with corrugation patterns are investigated. Excitonic modes are obtained ...
    • Two-temperature Ising model at an exact limit 

      Sanlı, Ceyda (Bilkent University, 2008)
      We analyze the order-disorder transition for a two dimensional Ising model. We consider a ferromagnetic exchange interaction between the nearest neighbor Ising spins. The spin exchanges are introduced in two different ...
    • Ultra-low noise fiber laser systems and their applications 

      Budunoğlu, İbrahim Levent (Bilkent University, 2014)
      Fiber laser systems are intensely studied for and already utilized in a wide range of scientific, biomedical and industrial applications. Scientifically, fiber lasers are widely used for spectroscopy, laser-matter ...
    • Unconventional superconductivity in two dimensional time reversal symmetric noncentrosymmetric superconductors 

      Günay, Mehmet (Bilkent University, 2017-09)
      In this thesis we study unconventional pairing observed in noncentrosymmetric superconductors by using spin dependent pairing potentials under the maximal C∞v and the time reversal symmetries (Θ-phase). The lack of ...
    • A variational approech to stationary and rotating Bose-Einstein condensates 

      Keçeli, Murat (Bilkent University, 2006)
      After the experimental demonstration of Bose-Einstein condensation (BEC) in alkali gases [6, 7, 18], the number of theoretical and experimental papers on ultracold atomic physics increased enormously [48]. BEC experiments ...
    • Variational Monte Carlo calculations for Bose-Hubbard model based on projected wavefunctions 

      Koç, Fulya (Bilkent University, 2014)
      Bose-Hubbard model is mainly used to describe and study the interactions between neutral atomic gases trapped in an optical lattice [1] and Josephson junction arrays [2]. It is one of the toy models to understand quantum ...
    • Variational Monte Carlo study of two dimensional charged bosons 

      Karakuzu, Seher (Bilkent University, 2014-09)
      We studied the ground state properties of 2D charged Bosons interacting via Coulomb potential using the Variational Monte Carlo method. We start with the paper of McMillan [1] in which there are 3D Bosons interacting via ...
    • Variational study of interacting su-schrieffer-heeger model 

      Saleem, Luqman (Bilkent University, 2018-09)
      The interacting Su-Schrieffer-Heeger model with nearest neighbor interaction in one dimension at half-filling is studied. To obtain ground state wave function, the Baeriswyl variational wave function is extended to account ...
    • Vortex transfer in charged-neutral superfluid mixtures 

      Kaya, Semih (Bilkent University, 2013)
      Bose-Einstein Condensation (BEC) was introduced by Einstein 1925. It took 70 years to confirm BEC by experiments. BEC creates a suitable environment to observe macroscopic-quantum behavior. Condensates consist of ultracold ...
    • Ytterbium doped all-fiber integrated high power laser systems and their applications 

      Yılmaz, Saniye Sinem (Bilkent University, 2013)
      For the past decades, high-power laser technology has been developing rapidly all over the world. The scientific interest in fiber lasers stems from the rich nonlinear dynamics. Industrial interest is largely due to their ...