Department of Physics

Thermally induced bias error due to strain inhomogeneity through the fiber optic gyroscope coil

Osunluk, Berk; Ogut, Serdar; Özbay, Ekmel (OSA - The Optical Society, 2020-11)

One of the performance limits of a navigation grade fiber optic gyroscope is the bias error due to the thermal sensitivity of the fiber coil. Thermal stress inside the fiber coil is an important source of the bias error. ...

CVD synthesis and characterization of thin Mo2C crystals

Türker, F.; Caylan, Ö. R.; Mehmood, Naveed; Kasırga, Talip S.; Şevik, C.; Cambaz-Büke, G. (Wiley, 2020)

In this study, we present an investigation on the growth of thin Mo2C crystals via chemical vapor deposition using CH4. Optical microscopy (OM), scanning electron microscopy (SEM), atomic force microscopy(AFM), and Raman ...

Large scale compatible fabrication of gold capped titanium dioxide nanoantennas using a shadowing effect for photoelectrochemical water splitting

T. Gamze, Ulusoy-Ghobadi; Ghobadi, Amir; Karadaş, Ferdi; Özbay, Ekmel (Elsevier, 2020)

In this paper, a visible light driven plasmonic based photoelectrochemical water splitting (PEC-WS) cell is designed with an elegant two-step fabrication route. First, titanium dioxide (TiO2) nanowires (NWs) were synthesized ...

Scattering of spin-1/2 particles from a PT-symmetric complex potential

Özgün, Ege; Hakioğlu, T.; Özbay, Ekmel (IOP, 2020-07)

In this letter, we study the scattering of spin- 1 2 particles from a spin-independent parity time (PT )-symmetric complex potential, and for the first time, theoretically demonstrate the coexistence of PT -symmetric and ...

Thermal conductivity measurements in nanosheets via bolometric effect

Çakıroğlu, Onur; Mehmood, Naveed; Çiçek, Mert Miraç; Rasouli, Hamid Reza; Durgun, Engin; Kasırga, T. Serkan (IOP Publishing Ltd, 2020-03)

Thermal conductivity measurement techniques for materials with nanoscale dimensions require fabrication of very complicated devices or their applicability is limited to a class of materials. Discovery of new methods with ...

Counterflow in Bose gas bilayers: Collective modes and dissipationless drag

Abedinpour, S. H.; Tanatar, Bilal (Institute for Low Temperature Physics and Engineering, 2020-03)

We investigate the collective density oscillations and dissipationless drag effect in bilayer structures of ultra-cold bosons in the presence of counterflow. We consider different types of inter-particle interactions and ...

Structural parameters and electronic properties of 2D carbon allotrope: Graphene with a kagome lattice structure

Sarıkavak-Lisesivdin, B.; Lisesivdin, S. B.; Özbay, Ekmel; Jelezko, F. (Elsevier, 2020-09-14)

In this paper, the electronic properties of a carbon allotrope, graphene with a kagome lattice structure, are investigated. Spin-polarized density functional theory (DFT) calculations with Grimme dispersion corrections ...

Free-standing and supported phosphorene nanoflakes: Shape- and size-dependent properties

Özaydın, H. D.; Görkan, T.; Bakir, M. Y.; Üzengi Aktürk, O.; Gökoğlu, G.; Aktürk, E.; Çıracı, Salim (Elsevier, 2020-01-01)

The ultra-small sized nanomaterials are important for basic functional components of future nanoelectronics, spintronics and sensor devices. In this study, based on first-principles density functional theory, the free-standing ...

Exchange-Correlation effects and the quasiparticle properties in a two-dimensional dipolar fermi liquid

Seydi, I.; Abedinpour, S. H.; Asgari, R.; Tanatar, Bilal (Springer, 2020)

We investigate the effects of exchange and correlation on the quasiparticle properties such as the self-energy, the many-body effective mass and the renormalization constant in a two-dimensional system of ultracold dipolar ...

Intersection behavior of the current–voltage (I–V) characteristics of the (Au/Ni)/HfAlO3/n-Si (MIS) structure depends on the lighting intensity

Arslan, Engin; Badali, Y.; Altındal, Ş.; Özbay, Ekmel (Springer, 2020)

The current–voltage (I–V) and capacitance–voltage (C–V) behaviors of the (Au/Ni)/HfAlO3/n-Si (MIS) junctions at room temperature under white light with various intensities were investigated. The ln(I)–V curves show two ...

Improved Tmax estimation in GaN HEMTs using an equivalent hot point approximation

Odabaşı, Oğuz; Akar, Mehmet Ömer; Bütün, Bayram; Özbay, Ekmel (IEEE, 2020)

In this article, heat generation distribution and maximum device temperature of gallium-nitride (GaN) high-electron-mobility transistors (HEMTs) are investigated by using the 2-D electrothermal and finite-element method ...

Ultraminiature antennas combining subwavelength resonators and a very-high-ε uniform substrate: the case of lithium niobate

Serebryannikov, A. E.; Gökkavas, Mutlu; Gündoğdu, Tamara Funda; Volski, V.; Vandenbosch, G. A. E.; Vasylchenko, A.; Özbay, Ekmel (IEEE, 2020)

Combining the effects of subwavelength resonators and very-high-permittivity substrates enables a high extent of miniaturization, even for very simple, split-loop resonators. Here, we demonstrate how requirements to the ...

Spectrally wide-range-tunable, efficient, and bright colloidal light-emitting diodes of quasi-2D nanoplatelets enabled by engineered alloyed heterostructures

Altıntaş, Yemliha; Liu, B.; Hernández-Martínez, P. L.; Gheshlaghi, Negar; Shabani, Farzan; Sharma, Manoj; Wang, L.; Sun, H.; Mutlugün, Evren; Demir, Hilmi Volkan (American Chemical Society, 2020-08)

Recently, there has been tremendous interest in the synthesis and optoelectronic applications of quasi-two-dimensional colloidal nanoplatelets (NPLs). Thanks to the ultranarrow emission linewidth, high-extinction coefficient, ...

In silico activity of AS1411 aptamer against nucleolin of cancer cells

Farahbakhsh, Z.; Zamani, M. R.; Rafienia, M.; Gülseren, Oğuz; Mirzaei, M. (Iranian Pediatric Hematology and Oncology Society, 2020)

Background: It has been expected that AS1411 aptamer could work against the cancer cells. Although the general information is available, there is still lack of details for the purpose. Therefore, activity of AS1411 aptamer ...

Characteristic temperatures of a triplon system of dimerized quantum magnets

Rakhimov, Abdulla; Nishonov, M.; Rani, Luxmi; Tanatar, Bilal (World Scientific, 2020)

Exploiting the analogy between ultracold atomic gases and the system of triplons, we study magneto-thermodynamic properties of dimerized quantum magnets in the framework of Bose–Einstein condensation (BEC). Particularly, ...

Trion-mediated förster resonance energy transfer and optical gating effect in WS2/hBN/MoSe2 heterojunction

Hu, Z.; Hernández-Martínez, P. L.; Liu, X.; Amara, M. R.; Zhao, W.; Watanabe, K.; Taniguchi, T.; Demir, Hilmi Volkan (American Chemical Society, 2020-09)

van der Waals two-dimensional layered heterostructures have recently emerged as a platform, where the interlayer couplings give rise to interesting physics and multifunctionalities in optoelectronics. Such couplings can ...

Magneto-optics of excitons interacting with magnetic ions in CdSe/CdMnS colloidal nanoplatelets

Shornikova, E. V.; Yakovlev, D. R.; Tolmachev, D. O.; Ivanov, V. Y.; Kalitukha, I. V.; Sapega, V. F.; Kudlacik, D.; Kusrayev, Y. G.; Golovatenko, A. A.; Shendre, S.; Delikanlı, Savaş; Demir, Hilmi Volkan; Bayer, M. (American Chemical Society, 2020-06)

Excitons in diluted magnetic semiconductors represent excellent probes for studying the magnetic properties of these materials. Various magneto-optical effects, which depend sensitively on the exchange interaction of the ...