Y.Sandy Berkovski
Bilkent University, Department of Philosophy

Date : May 9, 2012 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

My purpose in this talk is to address the relevance of Kant’s theory of space to the contemporary debate. For the past forty years an intense debate has been ranging on with regard to the nature of space between substantivalists and relationalists, neo-Newtonians and neo-Leibnizians.

Kant’s theory has not been a live option. Is there a good reason for this neglect? After examining Kant’s arguments, I will draw the conclusion that the neglect is largely justified.

Prof.Dr.Oğuz Gülseren
Bilkent University, Department of Physics

Date :May 2, 2012 (Wednesday)
Time: 15:40
Place: SBZ-14

ABSTRACT

Fully understanding of most of material properties needs an atomistic description from quantum mechanics. This is also true even for explaining an experimental data, especially for the systems involving nanostructures. However, the solution of the Schrodinger equation for such a many-body system is complicated if it is not impossible. To this end, we present the investigation of several state-of-the-art systems from first-principles calculations based on the density functional theory. Examples will include Hall conductance of graphene, Li intercalation of carbon nanotubes and bilayer graphene for battery applications, nature of the polymer-nanotube interaction, and titania nanostructures for dye-sensitized solar cells.

Applications consisting of a resume, a statement of teaching philosophy, a brief (3-page limit) statement of research interests, and the names and addresses of three references, should be submitted, preferably via email, to the Search Committee: Faculty Search Committee, Department of Physics, Bilkent University, Ankara, 06800 TURKEY Email: physics-search@fen.bilkent.edu.tr. Applications will be reviewed as they are received on an ongoing basis and the search will continue until the positions are filled. Web page: http://www.fen.bilkent.edu.tr/~physics

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Giovanni Volpe
Bilkent University, Department of Physics

Date : April 18, 2012 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

In recent years, active Brownian motion has attracted a lot of interest. Differently from simple Brownian motion, which is dominated by random fluctuations, active Brownian particles, e.g. bacteria, feature an interplay between random fluctuations and active swimming. Various model systems have been proposed for its study, e.g. Janus particles in a water-hydrogen peroxide. We propose a novel model systems where the swimming behaviour of the particles can be tuned by the intensity of illumination. We show how this leads to the possibility of studying the behaviour of active Brownian particles under new conditions, e.g. swimming behaviour depended on the particle position, and in new environments, e.g. non-homogenous and porous media. We also show how this may have applications for the study of the behaviour of bacteria.

Sondan Durukanoğlu Feyiz
Faculty of Engineering and Natural Sciences, Sabanci University

Date : April 11, 2012 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

In my talk, I will present results of molecular static calculations to investigate strain-induced structural and vibrational properties of metal nanowires. Our calculations demonstrates that due to substantially increased compressive strain in the core of the silver nanowire, induced by the applied tensile strain along the length direction, the fcc wire undergoes a structural phase transition into a tubular wire, in a perfect agreement with the experimental observation. Calculations for the vibrational density of states (VDOS) of a strain-free Cu nanowire, on the other hand, show quite distinctive characteristics compared to that of a bulk atom, the most striking feature of which is the existence of high frequency modes above the top of the bulk spectrum. We, additionally, find that while the high frequency band above the top of the bulk phonon shifts to higher frequencies, the characteristics at low frequencies remains almost the same upon stretching the nanowire along the axial direction.

Doç.Dr.Burak Özbağcı
Koç University, College of Sciences

Date : April 4, 2012 (Wednesday)
Time: 15:40
Place: Faculty of Science Building, B Block Seminar Room (SBZ14)

ABSTRACT

Prof. Özbagci will talk about 7-dimensional exotic spheres of John Milnor who won the Abel Prize in 2011 for his pioneering discoveries in topology, geometry and algebra.

Nejat Bulut
Izmir Institute of Technology

Date : March 21, 2012 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

The Haldane-Anderson model of a transition-metal impurity embedded in a semiconductor host can be used to describe the electronic state of both the Dilute Magnetic Semiconductors (DMS) and the metalloproteins. Here, as examples to these materials we consider GaAs with Mn impurities and hemoglobin, where Fe can also be considered as an impurity. In order to study these systems, we combine the Density Functional Theory (DFT) with the Quantum Monte Carlo (QMC) technique. In particular, we first use the DFT to calculate the host band structure and the impurity-host hybridization matrix elements, which serve as input parameters for the Haldane-Anderson model. Next, we perform the QMC simulations with these realistic model parameters. For the case of (Ga,Mn)As, the DFT+QMC approach leads to an impurity bound state located ~100meV above the top of the valence band in agreement with the experimental value of 110meV. Hence, it is possible to use the DFT+QMC approach to obtain reliable results for these types of systems. In particular, this approach could find wide use in revealing the electronic state of proteins and enzymes.

Ramiz Hamid
TÜBİTAK, Ulusal Metroloji Enstitüsü (UME)

Date : March 14, 2012 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

In this seminar, we will present displacement measurements with picometer level accuracy using differential Fabry-Perot interferometers and frequency stabilized external cavity diode lasers (ECDL). One of the lasers is locked to the cavity length of the tracking channel of the differential Fabry – Perot interferometer (FPI) using transmission or reflection resonances. The second laser is locked to the Rb atomic transitions (780 nm) or to the second channel of FPI. The change in cavity length of the interferometer introduce a change in the frequency of the laser and beat frequency signal between the two lasers is used for analysis of displacement measurement. Detailed information about developed lasers and interferometers will be presented.Under the European Metrology Research Programme funded NANOTRACE project, we compared the optical interferometer developed at TÜBİTAK UME with the X-ray interferometer developed by NPL (UK) and PTB (Germany).
X-ray interferometry is emerging as an important tool for dimensional nanometrology both for sub nanometre measurement and displacement. It has been used to verify the performance of the next generation of displacement measuring optical interferometers within the European Metrology Research Programme project NANOTRACE. Within this project a more detailed set of comparison measurements between the x-ray interferometer and a Dual Channel Fabry Perot (DFPI) optical interferometer have been made to demonstrate the capabilities of both instruments for picometre displacement metrology.
In this seminar comparison results between TÜBİTAK UME optical interferometer and X-ray interferometer with less than 5 pm will be presented.

İhsan Gürsel
Bilkent University, Dept. of Molecular Biology and Genetics

Date : March 7, 2012 (Wednesday)
Time: 15:40
Place: Faculty of Science Building, B Block Seminar Room (SBZ14)

ABSTRACT

In this presentation, I will describe the rationale behind this year`s Nobel Awards on Physiology and Medicine. This includes the sad story about Dr. Ralph Steinman, and a controversy regarding Dr. Jules Hoffmann. As my Lab efforts are parallel to these laureates` research themes, I will also summarize our recent Lab activities and describe you the major reason why we try to harness these nucleic acids as immunotherapeutic agents. I will specifically focus on how in our Lab, we formulate CpG ODNs and other nucleic acid based TLR ligands for therapeutic vaccine development. In brief, I will mainly focus on the development of nucleic acid containing nanoliposomes, polysaccharide nanocomplexes, modified montanide nano-emulsions, self-aggregating dendrimeric nanoparticles, and cell derived exosome nanovesicles as effective vaccine carriers against viral or bacterial infections as well as their prospects to be utilized as anti-cancer agents.

Alexander Klyachko
Bilkent University, Department of Mathematics

Date : February 22, 2012 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

In his ground breaking papers John Bell revealed that
(i) Every state of two dimensional quantum systems, e.g. spin ½ state, admits a hidden variables model, despite von Neumann’s claim to the contrary.

(ii) No such interpretation is possible for an entangled state of two qubits. Moreover, he devised the famous inequalities, named after him, that allow to test this philosophical question experimentally.

In the talk I will fill the dimensionality gap and show that every non-coherent state of three dimensional spin-one systems is incompatible with the hidden variables model. This means the quantum reality can’t be modeled by dice tossing. This quantum
mechanical prediction can be tested experimentally by the so called pentagram inequality. The actual experiment has been performed recently by Anton Zeilinger group in Vienna and published in Nature, {\bf 474}, 490 (2011). In a sense, it confirms the Einstein dictum: “God doesn’t play dice”.

All necessary concepts will be explained in the talk to make it accessible for students.

26 April 2012, 12:40-13:30

• Mehmet Günay: Fang. K, Yu Z., and Fan S. “Photonic Aharonov-Bohm Effect Based on Dynamic Modulation”, Phys. Rev. Lett. 108, 153901 (2012) [Link]
• Parviz Elahi: Boyd RW., and Shi Z. “How to hide in time”, Nature 481, 35–36 (2012) [Link]

3 May 2012, 12:40-13:30

• Ertuğrul Karademir: Sansoni L. et al. “Two-Particle Bosonic-Fermionic Quantum Walk via Integrated Photonics”, Phys. Rev. Lett. 108, 010502 (2012) [Link]
• Erçağ Pinçe: Pikovski I. et al. “Probing Planck-scale physics with quantum optics”, Nature Physics, Advanced Online Publication (2012) [Link]

10 May 2012, 12:40-13:30

• Balazs Hetenyi: Qi X-L and Zhang S-C “The quantum spin Hall effect and topological insulators”, Phys. Today 63(1), 33 (2010) [Link]
• Ozan Aktaş: Kippenberg TJ., Holzwarth R., and Diddams SA. “Microresonator-Based Optical Frequency Combs” , Science 332 (6029), 555-559 (2011) [Link]

All interested are cordially invited

You can find schedule and paper list of the previous semester here.

Emre Togan
Harvard University, Department of Physics

Date : January 11, 2012 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

Quantum optical techniques can be applied to monitor and control individual atom-like impurities, and their local environment, in the solid state. This talk will focus on applications of these techniques to quantum control of nitrogen vacancy (NV) centers in diamond.
Specifically, we will demonstrate that Coherent Population Trapping can be used for optical cooling, real-time measurement and manipulation of nuclear spin dynamics surrounding NV centers. Finally, potential applications of these techniques to nanoscale magnetometry and realization of quantum networks will be discussed.

Taner Yıldırım
UPENN and NIST

Date: December 28, 2011 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

The Materials Genome is a new initiative to develop an infrastructure to accelerate advanced materials discovery and deployment in real world applications. The success of this initiative depends on being able to predict and design new materials with desired properties from from-first principles modelling and theory and then test these predictions experimentally. Over the past decade, there has been major advances in both computer power and software applications, giving us access to length and time scales and number of atoms that are needed to understand and design new materials and science with predictive power.

In this talk, I will give a sneak preview of several projects that exemplify the power of combined first-principles computation, theory and neutron scattering studies to understand properties of a wide range of materials classes and predict/design new ones. In particular I will consider systems that are of great fundamental and practical interest. Systems will include hydrogen-storage/carbon-capture materials based on graphene oxides and unusual superconductors, such as new iron pnictides as well as organic superconductors such as metal-doped Picene.We will make predictions for new superconductors based on small organic molecules and few-layer graphene doped with metals.

Demet Gülen
Physics Department, M.E.T.U

Date : December 21, 2011 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

Advances in thin film technologies have enabled growth of extremely high quality films of various materials for integrated circuit (IC) applications. Ferroelectric materials have attracted great interest in the course of these developments as functional components where response to an external stimulus is usually sought to generate a signal or store charge for any purpose. These materials have also been considered as memory elements owing to their hysteresis in the applied field-polarization. The miniaturization of such components, as with any other component in ICs have both pushed the boundaries of what one might call “thin films” and given the research groups the motivation to study size effects in ferroelectric films. Interface and defect phenomena that have often been neglected in bulk crystals, have turned out to be the sole factor which determine the electrical properties of ferroelectric films. Moreover, growth of ferroelectric films on misfitting substrates have enabled tailoring of the strain state to stabilize a desired electrical property depending on the application. In this talk, I will try to summarize the effects of misfit strain on ferroelectric thin films and how interfaces and defects come into play when discussing functionality of these structures in reduced dimensions. I will also mention our recent computational work focusing on the phase transition characteristics of ferroelectric-paraelectric superlattices. Finally, I will give a glimpse of our latest experimental efforts to reduce leakage currents in BiFeO3 films, a ferroelectric with an antiferromagnet ordering at room temperature.

January 10, Tuesday

January 11, Wednesday

January 12, Thursday

January 13, Friday

January 14, Saturday

January 16, Monday

January 17, Tuesday

January 18, Wednesday

January 19, Thursday

Burç Mısırlıoğlu
Faculty of Engineering and Natural Sciences, Sabancı University

Date : December 14, 2011 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

Advances in thin film technologies have enabled growth of extremely high quality films of various materials for integrated circuit (IC) applications. Ferroelectric materials have attracted great interest in the course of these developments as functional components where response to an external stimulus is usually sought to generate a signal or store charge for any purpose. These materials have also been considered as memory elements owing to their hysteresis in the applied field-polarization. The miniaturization of such components, as with any other component in ICs have both pushed the boundaries of what one might call “thin films” and given the research groups the motivation to study size effects in ferroelectric films. Interface and defect phenomena that have often been neglected in bulk crystals, have turned out to be the sole factor which determine the electrical properties of ferroelectric films. Moreover, growth of ferroelectric films on misfitting substrates have enabled tailoring of the strain state to stabilize a desired electrical property depending on the application. In this talk, I will try to summarize the effects of misfit strain on ferroelectric thin films and how interfaces and defects come into play when discussing functionality of these structures in reduced dimensions. I will also mention our recent computational work focusing on the phase transition characteristics of ferroelectric-paraelectric superlattices. Finally, I will give a glimpse of our latest experimental efforts to reduce leakage currents in BiFeO3 films, a ferroelectric with an antiferromagnet ordering at room temperature.

Asst. Prof. Dr. Menderes Işkın
Department of Physics, Koç University

Date : November 30, 2011 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

With the ultimate success of techniques for trapping and cooling atomic gases developed and improved gradually since the 1980′s, atomic Fermi gases have emerged as unique testing grounds for many theories of exotic matter in nature, allowing for the creation of complex yet very accessible and controllable many-body quantum systems. For instance, a major breakthrough was achieved with the variation of the attractive interaction between atoms from two hyperfine states of Lithium-6 (or Potassium-40). The tuning of interactions permits the ground state of the system to evolve smoothly from a weak coupling Bardeen-Cooper-Schrieffer (BCS) limit of largely overlapping Cooper pairs to a strong coupling regime of tightly-bound bosonic molecules, which undergo Bose-Einstein condensation (BEC).

Given that the recent experimental studies on spin-orbit coupled Bose gases had a great success, one of the current frontiers in cold atom research is the study of spin-orbit coupled Fermi gases. In this talk, following an overview of earlier theoretical and experimental works on the usual BCS-BEC crossover problem, I will present our new results for the spin-orbit coupled systems. I will analyze both the ground state and finite temperature phase diagrams for uniform systems [1]. In particular, I will show that the topological structure of the ground-state phase diagrams is quite robust against the effects of anisotropy of the spin-orbit coupling. I will also show that the critical condensation temperature increases considerably in the molecular BEC limit. Depending on my timing, I may also present our very recent results on the vortex core and edge states in these systems [2].

[1] M. Iskin and A. L. Subaşı, Phys. Rev. Lett. 107, 050402 (2011); and Phys. Rev. A 84, 043621 (2011).
[2] M. Iskin, (to be published)

Assoc. Prof. Afif Sıddiki

Date : November 23, 2011 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

At low temperatures, low-dimensional electron systems show numerous peculiar quantum transport properties. One of the most interesting of such transport systems are the particle interferometers.
Interferometers like Mach-Zehnder and Aharanov-Bohm are induced in a two-dimensional electron system (2DES) by metallic gate electrodes or chemical etching. The strong magnetic field applied perpendicular to the plane of the interferometers, quantizes the current carrying states and generates edge states where the current is carried without backscattering, i.e. ballistic transport. These quantized edge states replace the (monochromatic) light beams at the optical versions of the optical interferometer(s), therefore a coherent transport takes place.
Various unexpected findings of recent experiments performed at these (quantum Hall based) interferometers, indicate that an accurate treatment of interaction effects, taking full and realistic account of sample and geometry dependent details, is essential for a satisfactory understanding of the observed phenomena, such as the path length independent interference pattern. In this talk I will report on the findings of a promissing theoretical canditate, namely the screening/interaction theory of the integer Hall effect. This approach was able to explain microscopically, both the vanishing Longitudinal resistance and the exact quantization of the plateaus, together with the transition between the plateaus. The measurements under quantized Hall conditions (T2 Tesla) are not only performed considering integer charged particles, however, are also performed using fractionally charged (quasi-) particles which present interference patterns as well, and the patterns cannot be explained within non-interacting single particle theories. Here, I will address these issues using the self-consistent solution schemes of the Schrödinger-Poisson equations concerning the particle interferometers in various complex geometries (such as Mach-Zehnder and Aharonov-Bohm), within Hartree and spin dependent generalizations thereof, utilizing density functional theories. In doing so, we build on our previous work with this method, which was shown to describe successfully various subtle geometry-dependent effects observed in quantum Hall systems, and investigate different working regimes of the interferometers such as high/low temperature and magnetic field.

Prof. Dimitris Alexandropoulos
University of Patras

Date : November 16, 2011 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

μ-ring resonators have emerged over recent years as a multifunctional platform towards photonics VLSI. The possibility to fabricate these on various photonic material systems and the structural simplicity that they offer has motivated the research community that has produced an appreciable technological know-how with respect to material aspects, fabrication techniques, design issues and functionalities. The scope of the talk is to analyze the fundamental concepts behind μ-rings from the application viewpoint. To this end, after a review of μ-rings’ key characteristics, waveguide designs that ensure monomode operation will be discussed as well as design schemes for fabrication misalignment tolerant structures. The application potential of μ-rings will be evaluated for lasers, active racetrack structures for sensing and active filters, as well as optical bistable μ-rings for processing functionalities.

Anyone interested is cordially invited.

Asst. Prof. Dr. Balazs Hetényi
I.D. Bilkent University

Date : October 26, 2011 (Wednesday)
Time: 15:40
Place: SA 240

ABSTRACT

The Gutzwiller approximation (GA) is a solution scheme for projected wavefunctions, such as the Gutzwiller wave-function(GWF).The GWF can be constructed by projecting out charge fluctuations from the Fermi sea. When the GA is applied to the GWF the Brinkman-Rice metal-insulator transition (MIT) results at half-filling, a phase transition in which the metallic state undergoes localization as the interaction strength is increased (thought to correspond to ”bad metals” such as V2 O3 ), the insulating state is completely localized (zero double occupations). Hence the insulating state is poorly described. Nevertheless, the Brinkman-Rice picture has provided a basis for understanding strongly correlated systems, and has even lead to interesting applications, such as the Brinkman-Rice transistor. Here the GA is applied to the Baeriswyl and the Baeriswyl-Gutzwiller wavefunctions (BWF and BGWF). The BWF is arrived at by acting with the kinetic energy operator on a maximally insulating state. For the BWF at half-filling a MIT results in which the metallic state is the simple Hartree-Fock solution, the insulating state, however, is one in which charge fluctuations due to exciton binding are present. For the BGWF the MIT occurs between the Gutzwiller metal and the excitonic insulator. Away from half-filling the BWF and BGWF describe a metallic state with bound excitons present. Such a scenario is thought to exist in carbon nanotubes. The variational scheme described here can be seen as a step towards momentum functional theory, the momentum analog of the well-known Hohenberg-Kohndensity functional theory. The time-dependent generalization of the above variational schemes and their application to calculate spectra and quantum quenches will also be presented along with some preliminary results. If time permits a few remarks on new results regarding the theory of polarization will also be included.

Dr. Feridun Ay
University of Twente MESA+ Institute

Date: October 19, 2011 (Wednesday)
Time: 15:40
Place: Faculty of Science Building, Room 240

ABSTRACT

There is a growing demand for optical amplifiers capable of amplifying high rate signals and for on-chip micro-lasers with tunable output wavelengths. Specific areas of application of such devices include trace-gas detection, lab-on-a-chip, optical-coherent communications, optical beam-forming, and board level optical interconnects. In the first part of the talk we will review our latest results on development of rare-earth ion doped waveguide amplifiers for use in optical backplanes envisaged to replace the currently existing electronic printed circuit technology. We will discuss integration approaches of such technology with silicon photonics and optical backplanes. We will also report on utilization and optimization of the focused-ion-beam (FIB) technique for the fabrication of nanostructures and microcavities on optical waveguides for realization of integrated photonic devices. In particular, we will report the first on-chip waveguide laser in solid state double tungstates and realization of ring micro-laser devices compatible with silicon photonics.

Prof. Dr. Bayram Tekin
Department of Physics
Middle East Technical University

Date: October 12, 2011 (Wednesday)
Time: 16:00
Place: Faculty of Science Building, Room 240

ABSTRACT

Recalling that physics is a curiosity-driven science. I will discuss
three somewhat related topics: 1) How simple questions led to great
discoveries; 2) How beautiful but unsuccessful ideas are recycled;
3) Open problems in fundamental physics.

Dr. Karl-Heinz Heinig
Helmholtz-Zentrum Dresden-Rossendorf

Date: October 5, 2011 (Wednesday)
Time: 15:40
Place: Faculty of Science Building, Room 240

ABSTRACT

This presentation consists of three parts:
(i) The self-organization of regular morphologies on elemental semiconductor surfaces under irradiation with ions will be discussed. It will be proven that at least for low-energy ions the driving force for this pattern formation is not sputtering, as it was claimed in most published papers so far, but ion impact induced mass drift.
(ii) Our progress on shaping of metal and semiconductor nanospheres embedded in silica using swift heavy ions will be reported. Metal spheres can be shaped into rods and quadruples, whereas germanium nanospheres have been shaped into disks. It will be shown that electronic stopping power melts the nanoparticles, and that the volume change upon melting is the driving force for shaping.
(iii) Nanowires have been synthesized by FIB implantation, e.g. CoSi2 wires in silicon. By subsequent thermal treatment, nanocluster chains have been formed by a controlled decay of these wires. Computer experiments will show that rather complex nanostructures can be fabricated by this technique.

Office: ARL-101

Phone: +90 312 290 1579

eMail: aydinli[at]fen.bilkent.edu.tr

Professor, Ph.D.: Condensed Matter Physics, University of Virginia, 1981

Raman and photoluminescence in compound semiconductor structures, physics of nanostructures, physics and technology of optoelectronic devices, surface physics, beam-solid interactions.

Selected Publications

• S. Balci, E. Karademir, C. Kocabas, and A. Aydinli, “Direct imaging of localized surface plasmon polaritons”, Optics Letters vol. 36, Issue 17, pp. 3401-3403 (2011)
• S. Balci, A. Kocabas, C. Kocabas and A. Aydinli, “Localization of surface plasmon polaritons in hexagonal arrays of Moiré cavities”, Appl. Phys. Lett. 98, 031101 (2011)
• S. Balci, A. Kocabas, C. Kocabas, A. Aydinli, “Slowing surface plasmon polaritons on plasmonic coupled cavities by tuning grating grooves,” Applied Physics Letters, vol. 97, pp. 131103-1–3 (2010) (PDF)
• S. Balci, M. Karabiyik, A. Kocabas, C. Kocabas, A. Aydinli, “Coupled Plasmonic Cavities on Moire Surfaces,” Plasmonics, vol. 5, pp. 429-436 (2010)
• P. Basa, P. Petrik, M. Fried, A. Dana, A. Aydinli, S. Fossi, T.G. Finstad, “Spectroscopic Ellipsometric Study of Ge Nanocrystals Embedded in SiO₂ Using Parametric Models,” Physica Status Solidi A, vol. 5, pp. 1332-1336 (2009)
• A. Kocabas, S.S. Senlik, A. Aydinli, “Slowing Down Surface Plasmons on a Moire Surface,” Physical Review Letters, vol. 102, pp. 063901-1–4 (2009)
• S. Olcum, A. Kocabas, G. Ertas, A. Atalar, A. Aydinli, “Tunable surface plasmon resonance on an elastomeric substrate,” Optics Express, vol. 17, pp. 8542-8547 (2009) (PDF)
• S.S. Senlik, A. Kocabas, A. Aydinli, “Grating based plasmonic band gap cavities,” Optics Express, vol. 17, pp. 15541-15549 (2009) (PDF)
• I.B. Akca, A. Dana, A. Aydinli, M. Rossetti, L. Li, A. Fiore, N. Dagli, “Electro-Optic and Electro-absorption characterization of InAs quantum dot waveguides,” Optics Express, vol. 16, pp. 3439-3444 (2008) (PDF)
• I.B. Akca, A. Dana, A. Aydinli, R. Turan, “Comparison of Electron and Hole Charge-Discharge Dynamics in Germanium Nanocrystal Flash Memories,” Applied Physics Letters, vol. 92, pp. 052103-1–3 (2008) (PDF)

Office: UNAM-205

Phone: +90 312 290 3500 or 2513

eMail: mb[at]fen.bilkent.edu.tr

Assistant Professor, Ph.D.: Physics, Bilkent University, 2002

Web Site

Microstructured fibers and fiber devices, photonic band gap materials, left-handed metamaterials, materials for infrared optics, synthetic optoelectronic devices, nonlinearity in amorphous semiconductors, nanophotonics, fiber based sensors.

Selected Publications

• Bio-inspired optoelectronic nose with nanostructured wavelength scalable hollow-core infrared fibers A. Yildirim, M. Vural, M. Yaman, and Mehmet Bayindir Advanced Materials, volume 23, page 1263 (2011)
• Size-dependent structural coloring in large scale core-shell nanowires T. Khudiyev, E. Ozgur, M. Yaman, and Mehmet Bayindir Nano Letters, volume 11, page 4661 (2011)
• Mecit Yaman, Tural Khudiyev, Erol Ozgur, Mehmet Kanik, Ozan Aktas, Ekin O. Ozgur, Hakan Deniz, Enes Korkut & Mehmet Bayindir, “Arrays of indefinitely long uniform nanowires and nanotubes”, Nature Materials 10, 494–501 (2011)
• K. Gurel, B. Kaplan, H. Guner, M. Bayindir, A. Dana, “Resonant transmission of light through surface plasmon structures,” Applied Physics Letters, vol. 94, pp. 233102-1–3 (2009)
• K. Gurel, B. Kaplan, H. Guner, M. Bayindir, A. Dana, “A compact filter based on anomalous transmission in grating coupled plasmon resonance,” Applied Physics Letters, vol. 94, pp. 233102 (2009)
• B. Kaplan, H. Guner, O. Senlik, K. Gurel, M. Bayindir, A. Dana, “Tuning optical discs for plasmonic applications,” Plasmonics, vol. 4, pp. 237-243 (2009)
• S.T. Kasirga, Y.N. Ertas, M. Bayindir, “Microfluidics for reconfigurable electromagnetic matamaterials,” Applied Physics Letters, vol. 95, pp. (2009)
• H.E. Kondakci, M. Yaman, O. Koylu, A. Dana, M. Bayindir, “All-chalcogenide glass omnidirecional photonic band gap variable infrared filters,” Applied Physics Letters, vol. 94, pp. 111110-1–3 (2009) (PDF)
• T. Ozdemir, S. Atilgan, I. Kutuk, L.T. Yildirim, A. Tulek, M. Bayindir, E.U. Akkaya, “Solid state emissive BODIPY dyes with bulky substituents as spacers,” Organic Letters, vol. 11, pp. 2105-2107 (2009)

Office: A-220

Phone: +90 312 290 2511

eMail: bulutay[at]fen.bilkent.edu.tr

Associate Professor, Ph.D.: Electrical and Electronics Engineering, Middle East Technical University, 1997

Web Site

Theoretical semiconductor physics, light-matter interaction, nonlinear and quantum optics in nanocrystals.

Selected Publications

• C. Bulutay, C.M. Turgut, N.A. Zakhleniuk, “Carrier-induced refractive index change and optical absorption in wurtzite InN and GaN: Full-band approach,” Physical Review B, vol. 81, pp. 155206-1–10 (2010)
• C. Bulutay, K. Kulakci, R. Turan, “Stark effect, polarizability, and electroabsorption in silicon nanocrystals,” Physical Review B, vol. 81, pp. 125333-1–8 (2010)
• D.E. Yilmaz, C. Bulutay, T. Cagin, “Analysis of strain fields in silicon nanocrystals,” Applied Physics Letters, vol. 94, pp. 191914-1–3 (2009) (PDF)
• C. Bulutay, N.A. Zakhleniuk, “Carrier induced refractive index change in InN,” Physica Status Solidi C, vol. 5, pp. 511-513 (2008)
• C. Sevik, C. Bulutay, “Auger recombination and carrier multiplication in embedded silicon and germanium nanocrystals,” Physical Review B, vol. 77, pp. 125414 (2008)
• H. Yildirim, C. Bulutay, “Enhancement of optical switching parameter and third-order optical nonlinearities in embedded Si nanocrystals: A Theoretical Assessment,” Optics Communications,vol. 281, pp. 4118-4120 (2008)
• H. Yildirim, C. Bulutay, “Bound-state third-order optical nonlinearities of embedded germanium nanocrystals,” Physical Review B, vol. 78, pp. 115307-1–6 (2008)
• D.E. Yilmaz, C. Bulutay, T. Cagin, “Atomistic Structure simulation of silicon nanocrystals with suboxide acceleration,” J of Nanoscience and Nanotechnology, vol. 8, pp. 635-639 (2008)
• D.E. Yilmaz, C. Bulutay, T. Cagin, “Pathways of bond topology transitions at the interface of silicon nanocrystals and amorphous silica matrix,” Physical Review B, vol. 77, pp. 155306-1–5 (2008)
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