Browsing Theses - Department of Physics by Title
Now showing items 136-155 of 234
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A Monte Carlo study of Maxwell’s demon coupled to finite quantum heat baths
(Bilkent University, 2020-09)When Maxwell’s demon was introduced, it raised the question: Is there a way to decrease an isolated system’s entropy, even though it was forbidden by the second law of thermodynamics. Then, a new idea which considered ... -
Multi-exciton states in flexible Rydberg aggregates
(Bilkent University, 2017-07)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 ... -
Multi-frequency fluxgate magnetic force microscopy
(Bilkent University, 2008)In the recent years, progress in atomic force microscopy (AFM) led to the multifrequency imaging paradigm in which the cantilever-tip ensemble is simultaneously excited by several driving forces of different frequencies. ... -
Nanoscience for sustainable energy production
(Bilkent University, 2011)Hydrogen economy towards the utilization of hydrogen as a clean and sustainable energy source has three ingredients. These are (i) hydrogen production; (ii) hydrogen storage; and (iii) fuel cells. Optimization of fuel ... -
Negative refraction using true left-handed metamaterials
(Bilkent University, 2004)Left-handed materials and negative refraction attracted a great amount of attention in recent years due to their unique physical properties. It is possible to obtain a left-handed material by combining a novel artificial ... -
Non-boltzmann stationary distributions and non-equilibrium relations in active baths
(Bilkent University, 2016-10)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 ... -
Non-equilibrium steady state phase transitions of various statistical models
(Bilkent University, 2013)Non-equilibrium phase transitions of a number of systems are investigated by several methods. These systems are in contact with thermal baths with different temperatures and taken to be driven to the non-equilibrium ... -
Nonlinear and far-from-equilibrium dynamics of optical pulses in fiber oscillators
(Bilkent University, 2017-08)Fundamentals of mode locking of lasers have been extensively studied and well established for the last three decades. However, it continues to be an intensely studied field. The continued interest is, in part, due to the ... -
Novel approaches to control the propagation of electromagnetic waves : metamaterials and photonic crystals
(Bilkent University, 2007)Applications in areas such as photonics, antennas, imaging and optics require the control of propagation of electromagnetic waves and the control of emission of electromagnetic radiation. Achievements in three key research ... -
Novel approaches to ultrafast fiber laser design for ablation-cooled material removal
(Bilkent University, 2016-11)The past few decades in particular have witnessed the tremendous beneficial impact of innovations in laser technology ranging from biomedical to industrial applications in response to enhancing community's quality of life. ... -
Novel concepts in high power semiconductor lasers
(Bilkent University, 2018-12)This doctoral thesis deals with innovations to the cavity optics of high power semiconductor lasers emitting light at 9xx nm. High power laser diodes are complex electronic and photonic systems. Developments in epitaxial ... -
Novel design-based complex nanostructures in hybrid core-shell architectures for high-efficiency light generation
(Bilkent University, 2010)Recent developments in nanoscience and nanotechnology have given rise to the discovery of hybrid nanostructured multi-component materials that serve several tasks all at once. A very important and rapidly growing field ... -
Novel hybrid light emitting diodes with multiple assemblies of nanocrystals to generate and tune white light
(Bilkent University, 2007)Today approximately one third of the world population (about two billion people) in under-developed countries has no access to electricity and relies on unhealthy, costly and low-quality fuel-based lighting for home ... -
A novel method for thermal conductivity measurement of two dimensional materials
(Bilkent University, 2019-09)Thermal conductivity is a quantity which governs the heat transfer in a material. After increasing importance of efficiency in power generation systems and cooling mechanisms in micro-structures, many measurement methods ... -
Novel ultraviolet scintillators based on semiconductor quantum dot emitters for significantly enhanced photodetection and photovoltaics
(Bilkent University, 2007)Silicon photonics opens opportunities to realize optoelectronic devices directly on large-scale integrated electronics, leveraging advanced Si fabrication and computation capabilities. However, silicon is constrained in ... -
Nuclear spin relaxation and spin squeezing under electric quadrupole interaction
(Bilkent University, 2015-08)Nuclear spins dynamics recently gained prominence for semiconductor quantum information technologies. At least two rami cations can be mentioned within this context: rst, as a decoherence channel for carrier spin qubit ... -
On the strain in silicon nanocrystals
(Bilkent University, 2009)In this Thesis we present our achievements towards an understanding of atomistic strain mechanisms and interface chemistry in silicon nanocrystals. The structural control of silicon nanocrystals embedded in amorphous ... -
Optical and thermal dynamics of long wave quantum cascade lasers
(Bilkent University, 2018-09)Quantum Cascade Lasers (QCLs) are coherent light sources that make use of intraband transitions of wavefunction engineered semiconductor quantum wells. They have been designed to emit light in a wide spectral range; from ... -
Optical near field interaction of spherical quantum dots
(Bilkent University, 2012)Nanometer-sized materials can be used to make advanced photonic devices. However, as far as the conventional far-field light is concerned, the size of these photonic devices cannot be reduced beyond the diffraction limit ... -
Optomechanically induced transparency in a PT symmetric system
(Bilkent University, 2020-09)Optomechanical systems have attracted attention recently in various areas of physics, and are widely used with the purpose of laser cooling, gravitational wave detection, preparation of entangled states, cooling of ...