Dept. of Physics  Master's degree: Recent submissions
Now showing items 120 of 150

Haldane phase in the bondalternating spin1/2 XXZ chain: DMRG and fermionization studies
(Bilkent University, 201901)In this thesis, the subject of study is the Haldane phase in bond  alternating XXZ chain with S =1/2. We firstly mapped our model to the fermionic chain by the use of standard JordanWigner Transformation, which leads ... 
Ground state energy of the fröhlich polaron as a function of dimensionality and the phonon coupling strength
(Bilkent University, 201809)We use the trial polaron wave function introduced by Devreese et al. [1] to estimate the ground state energies of the Fröhlich polaron over a broad range of the phonon coupling strength by a variational approach. We ... 
Investigation of thermoelectric properties of 2D βsilicon monotelluride (site)
(Bilkent University, 201809)Thermoelectric properties of novel 2D silicon monotelluride (SiTe) are studied using first principles calculations. The plane wave method based on density functional theory as implemented in Vienna ab initio simulation ... 
Largescale semiempirical pseudopotential electronic structure of selfassembled ingaas quantum dots
(Bilkent University, 201809)The socalled second quantum revolution emerged at the beginning of the second millennium, opening up a path to realization of spinqubitbased quantum computing by means of controlling and protecting quantum coherent ... 
Variational study of interacting suschriefferheeger model
(Bilkent University, 201809)The interacting SuSchriefferHeeger model with nearest neighbor interaction in one dimension at halffilling is studied. To obtain ground state wave function, the Baeriswyl variational wave function is extended to account ... 
Electrostatic correlations in inhomogeneous electrolytes
(Bilkent University, 201808)The fieldtheoretic approach is used to obtain the selfconsistent equations for inhomogeneuos symmetric electrolytes. The perturbative Green's function method is used to solve these selfconsistent equations for an ... 
Gravitational waves from binary black hole systems in inspiralling phase
(Bilkent University, 201807)Binary black hole systems have three phases: inspiralling, merger and ringdown phases. This thesis is a review of methods developed to study the inspiralling phase analytically. Those methods include post Minkowskian ... 
Hyperfine and electric quadrupolar interactiondriven loschmidt echo in nanoscale nuclear spin baths
(Bilkent University, 201807)Environmental dynamics in solid state matrix is of much importance for quantum information processing and storage purposes. Here, we first give a basic recipe to get Loschmidt echo (LE) which is a measure of decoherence ... 
Sonic Hawking Radiation from a blackhole laser
(Bilkent University, 201806)The quantum thermal radiation from a black hole (BH) known as “Hawking Radiation” or “Black Hole Evaporation” results from studying quantum fields in the curved spacetime of the horizon of a BH. Experimentally, the ... 
Investigation of optical residual absorption in graphene
(Bilkent University, 201803)Graphene, a 2dimensional crystal of carbon, can absorb 2.3% of light over a very broad spectrum. Doped graphene, however has a gap in optical absorption due to the Pauli blocking principle. For doped graphene, the interband ... 
Modeling of semiconductor devices based on quantum wells: quantum cascade laser as an example
(Bilkent University, 201802)It has been two decades since the quantumcascade lasers (QCLs) have emerged in 1994 for the first time. As time goes on, QCLs reach to higher points scientifically and economically and the usage of QCLs devices continually ... 
Model description of friction on planar and buckled two dimensional materials
(Bilkent University, 201801)The law of friction has been known since the 18th century but yet, the development on the tribology field was established in the last decades mainly by the invention of frictional force microscope (FFM), which enabled ... 
Tight binding modeling of two dimensional and quasitwo dimensional materials
(Bilkent University, 201710)Since the advent of graphene, twodimensional (2D) materials have consistently been studied owing to their exceptional electronic and optical properties. While graphene is completely twodimensional in nature, its other ... 
Energy and angular momentum transfer with circular Rydberg states
(Bilkent University, 201708)Circular states belong to a class of Rydberg states having maximum angular momentum. These states, compared to other Rydberg states, have longer lifetimes, and in the classical limit resemble circular Bohrlike orbits. ... 
Analysis of the magnetic translation group and investigation of a onedimensional topological model
(Bilkent University, 201708)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 ... 
First principles study of 2D gallium nitride and aluminium nitride in squareoctagon structure
(Bilkent University, 201708)This thesis, deals with the planar freestanding, singlelayer, squareoctagon (SO) structures of GaN and AlN. We investigated singlelayer and multilayer soGaN and soAlN structures, their stability, electronic properties ... 
Multiexciton states in flexible Rydberg aggregates
(Bilkent University, 201707)Flexible Rydberg aggregates, assemblies of highly excited atoms, provide a platform to investigate quantum phenomena like energy transport and conical intersections. This can be achieved by doping the aggregate with an ... 
Braph : a toolbox developed for brain graph analysis of various imaging modalities
(Bilkent University, 201703)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 BoseEinstein condensates using Gelfand Yaglom method
(Bilkent University, 201611)Nonlinear excitations of BoseEinstein 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 ... 
Nonboltzmann stationary distributions and nonequilibrium relations in active baths
(Bilkent University, 201610)Most natural and engineered processes, such as biomolecular reactions, protein folding, and population dynamics, occur far from equilibrium and, therefore, can not be treated within the framework of classical equilibrium ...