Browsing Theses - Department of Physics by Title
Now showing items 17-36 of 233
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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 ... -
Braph : a toolbox developed for brain graph analysis of various imaging modalities
(Bilkent University, 2017-03)Complex systems, like the human brain, are composed of a huge number of interacting elements showing complex patterns. Graph theory provides a mathematical toolbox for investigating the role of each element in these systems. ... -
Calculation of masses of dark solitons in 1D Bose-Einstein condensates using Gelfand Yaglom method
(Bilkent University, 2016-11)Nonlinear excitations of Bose-Einstein condensates (BEC) play important role in understanding the dynamics of BECs. Solitons, shape preserving wave packets, are the most fundamental nonlinear excitations of BECs. They ... -
Carrier dynamics in silicon and Germanium nanocrystals
(Bilkent University, 2008)This is a computational work on the Si and Ge nanocrystals (NCs) embedded in wide band gap host matrices. As the initial task, extensive ab initio work on the structural and electronic properties of various NC host ... -
Chalcogenide micro and nanostructures and applications
(Bilkent University, 2014)Chalcogenides, which are glasses consist of S, Se and Te elements, are promising materials for photonics as silicon for modern electronics, due to their extraordinary material properties such as high nonlinearity and ... -
Characterization and applications of negative-index metamaterials
(Bilkent University, 2008)Metamaterials offer novel electromagnetic properties and promising applications including negative refraction, flat-lenses, superlenses, cloaking devices. In this thesis, we characterized the negative-index metamaterials ... -
Characterization of photonic crystals at microwave frequencies
(Bilkent University, 1996)VVe investigated the surface reflection properties of layer-by-layer photonic crystals, for dielectric and metallic based photonic crystals. By using a FabryPerot cavity analogy with the reflection-phase information of ... -
Computational study of excitons and biexcitons in semiconductor core/shell nanocrystals of type I and type II
(Bilkent University, 2013)In this thesis, we studied electronic structure and optical properties of Type-I, Type-II, and quasi Type-II semiconductor nanocrystals (also known as colloidal quantum dots). For a parametric study, we developed quantum ... -
Construction of a scanning tunneling microscope and first results
(Bilkent University, 1990)In this thesis, construction of a Scanning Tunneling Microscope in air is explained. A step motor sample approach mechanism and a tripod scanner are used in the construction. Atomic resolution images of graphite samples ... -
Construction of an atomic force microscope operating in air and liquid
(Bilkent University, 2003)In this thesis, a new atomic force microscope capable of measuring in liquid and air has been introduced. The highly improved design of the instrument eliminates some of the technical problems which are occurred before. ... -
Controlled lateral and perpendicular motion of atoms on metal surfaces
(Bilkent University, 1994)Nanoscale modification of matter has been the subject of interest. Recently, several experimental studies have demonstrated that by using a scanning tunneling microscope one can translate atoms on metal surfaces to a ... -
Controlling electromagnetic waves with active graphene devices
(Bilkent University, 2015) -
Correlation effects in coupled quantum-well and quantum-wire systems
(Bilkent University, 2001) -
Dark current control in InAs/GaSb superlattice photodetectors
(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 ... -
Decoherence in open quantum systems : a realistic approach
(Bilkent University, 2006)Decoherence mechanisms of opcu quantum systems ın intcraction with an enviromental bath is investigated using the master equation formalism. Widely used two-level approximation is questioned. -
Deformation and finite size effects in cooperative molecular motors
(Bilkent University, 2002-07)Motor protein systems have been of considerable interest lately. In these studies muscle contraction is modeled as the sliding of two filaments made of protein particles over one another, that is the sliding of the ... -
Development of force fields for novel 2D materials for temperature dependent vibrational properties
(Bilkent University, 2019-09)A new era of nanodevice engineering has been started after fabricating graphene. This motivated vast number of researches for predicting, fabricating and utilizing 2D materials. Temperature dependent properties are ...
