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Now showing items 1-20 of 229
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33 Femtosecond Yb-doped optical frequency comb for frequency metrology applications
(Bilkent University, 2013)Optical frequency combs have enabled many applications (high precision spectroscopy, table-top optical frequency metrology, optical atomic clocks, etc.), received considerable attention and a Nobel Prize. In this thesis, ... -
A1GaN UV photodetectors : from micro to nano
(Bilkent University, 2011)The absorption edge of AlGaN based alloys can be tuned from deep UV to near UV by changing the composition. This enables the use of the material in various technological applications such as military, environmental ... -
Ab-initio study of iridium on silicon (001) surface
(Bilkent University, 2013)Self-assembled nanowire growth on semiconductor surface is based on deposing sub-monolayer material over the surface. Even though high resolution STM image gives plausible surface analysis, determination of the nanowire ... -
The adiabatic and non-adiabatic behavior of a particle in optical lattices
(Bilkent University, 2018-06)The cold atom experiments provide a clean and controlled environment for realizing many body systems. Recent realizations of artificial gauge fields and adjustable optical lattices paved the way for the study of effectively ... -
Adsorption and dissociation of hydrogen molecule on carbon nanotubes
(Bilkent University, 2004)Earlier, it has been suggested that carbon nanotubes can provide high storage capacity and other physical properties suitable for the fuel cell technologies. In this thesis we have investigated adsorption, desorption and ... -
Al(x)Ga(1-x)As/GaAs graded index separate confinement heterostructure single quantum well lasers
(Bilkent University, 1994)"Stimulated emission of photons could be produced in semiconductors by recombination of carriers injected across a p-n junction This idea was first suggested by Basov et al} in 1961. Soon afterwards diode lasers were ... -
Alteration of self-assembled patterns by microorganisms in evaporating droplets
(Bilkent University, 2016-08)The science of self-organization comprises a diverse range of processes where a disordered system of components form ordered pattern or structure spontaneously without any external instruction [1]. Plentiful examples of ... -
AlxGa1-xN based solar blind Schottky photodiodes
(Bilkent University, 2004)Photodetectors are essential components of optoelectronic integrated circuits and fiber optic communication systems. AlxGa1−xN is a promising material for optoelectronics and electronics. Applications include blue and ... -
Analysis of nonequilibrium steady-states
(Bilkent University, 2016-12)Non-equilibrium is the state of the almost all systems in the universe. Unlike equilibrium systems, they interfere with their surroundings which results in never ceasing uxes. There is no unified theory to understand these ... -
Analysis of the magnetic translation group and investigation of a one-dimensional topological model
(Bilkent University, 2017-08)The periodicity of a space lattice in presence of a uniform magnetic eld is preserved. During this thesis, we will study a set of modi ed translation operators which commute with the e ective Hamiltonian of an electron ... -
Analytic calculation of ground state properties of the 2d and 3d electron gas
(Bilkent University, 2015-06)The electron gas (2D and 3D) is a model which consists of interacting electrons moving in a uniform positive background. Its importance stems from the fact that a number of metals behave similarly, it provides the ... -
Approximation methods in the polaron theory: applications to low dimensionally confined polarons
(Bilkent University, 1996)The pelaron problem has been of interest in condensed matter physics cind held theory tor cibout half a century. Within the framework of Vcist variety of theoreticcil approximations, the bulk polaron properties have been ... -
Atomic force microscopy experiments on atomically thin materials
(Bilkent University, 2020-07)In 2004, successful isolation of graphene attracted immense attention of scientists because of atomic scale thickness and exotic functionalities. Regardless of graphene’s thickness and extraordinary properties only reason ... -
Atomic scale investigation of clean and epi-grown Si(001) surfaces using scanning tunneling microscopy
(Bilkent University, 1996)In this thesis, clean and epi-grown Si(001)(2x1)surfaces are analyzed by Scanning Tunneling Microscopy (STM). The STM and Ultra High Vacuum System (UHV) in which the microscope is installed, are described. A brief history ... -
Atomic theory of the scanning tunneling microscope
(Bilkent University, 1988)The Scanning Tunneling Microscope is proven to be one of the most powerful tools for surface structure determination. Present theories are able to explain the operation of the microscope when the tip is far from the ... -
Atomic, electronic, and transport properties of quantum point contacts on graphite surface
(Bilkent University, 1997) -
Ballistic transport and tunneling in small systems
(Bilkent University, 1990)Ballistic transport and tunneling of electrons in mesoscopic systems have become one of the most important subjects of condensed matter physics. The quantum point contacts and scanning tunneling microscope form the basic ... -
Beaming and localization of electromagnetic waves in periodic structures
(Bilkent University, 2010)We want to manipulate light for several applications: microscopy, data storage, leds, lasers, modulators, sensor and solarcells to make our life healthier, easier or more comfortable. However, especially in small scales ... -
Bias voltage control of a molecular spin valve
(Bilkent University, 2009)With the discovery of giant magneto resistance a new field called spintronics is emerged. Utilizing spin-degree of freedom of the electron as well as its charge, high-speed devices which consumes low energy can be designed. ... -
Boron nitride and graphene 2D nanostructures from first-principles
(Bilkent University, 2010)In this thesis, the structures as well as mechanical and electronic properties of various boron nitride (BN) and graphene based two dimensional (2D) nano-structures are investigated in detail from rst-principle calculations ...
