Browsing by Author "Gokcen, Dincer"

Now showing 1 - 6 of 6

Citation - WoS: 8
Citation - Scopus: 8
Analysis of Quantum Radar Cross-Section by Canonical Quantization Method (Full Quantum Theory)
(Ieee-inst Electrical Electronics Engineers inc, 2020) Salmanogli, Ahmad; Gokcen, Dincer
This article investigates the difference between two quantum-based theories to calculate the radar cross-section (RCS). Quantum radar cross-section (QRCS) has been commonly analyzed using the dipole approximation method, and the related results show that it can improve the sidelobe of the interference pattern in contrast to the classical methods. This study, on the other hand, utilizes the canonical quantization (or microscopic) method, which is a more comprehensive theory than the dipole approximation method to calculate the radar cross-section. It is shown that there are some similarities between two methods; nonetheless, there are some crucial quantities and factors that have been ignored in the dipole approximation methods. The main difference arises due to the interaction Hamiltonian that two methods relied on. The theoretical calculation shows some critical points suggesting that the dipole approximation method cannot cover all aspects of the radar cross-section calculation. To verify the mentioned point, we establish a new method in which the radar cross-section is calculated by merging the quantum approach with the method of moment (MoM), called quantum-method of moment (QMoM). The simulation results show that the newly established method is in harmony with the canonical quantization method.
Citation - WoS: 8
Citation - Scopus: 8
Design of quantum sensor to duplicate European Robins navigational system
(Elsevier Science Sa, 2021) Salmanogli, Ahmad; Gokcen, Dincer
In this article, we design a quantum device to duplicate the European Robins procedure to precisely deter-mine the migratory route. In the mentioned procedure, the important issue is the geomagnetic field effect on the magnetic momentum of the created radical pairs (triplet-singlet states) dancing with a special fre-quency. To duplicate the procedure, a quantum sensor consisting of two coincident tripartite systems is designed. Each tripartite system is independently excited with the entangled photons (signal and idler). The interesting point is that by manipulation of the system in the right condition, the microwave cavities modes separately affected by the entangled photons can be entangled. The entangled microwave photons play the same role as the triplet-singlet states present in the bird's navigational system. The key point in the design of the quantum sensor is that the entanglement between microwave photons can be strongly affected by the external magnetic field. In fact, this is the criterion employed by the quantum sensor to sense the magnetic field intensity and the direction. To analyze the system, the canonical quantization (or microscopic) method is used to determine the sensor's Hamiltonian, and also the system dynamics equations of motions are analytically derived using Heisenberg-Langevin equations. (c) 2021 Elsevier B.V. All rights reserved.
Citation - WoS: 20
Citation - Scopus: 20
Entanglement of Optical and Microcavity Modes by Means of an Optoelectronic System
(Amer Physical Soc, 2019) Salmanogli, Ahmad; Gokcen, Dincer; Gecim, H. Selcuk; 280089
Entanglement between optical and microwave cavity modes is a critical issue in illumination systems. Optomechanical systems are utilized to introduce coupling between the optical and microwave cavity modes. However, due to some restrictions of the optomechanical system, especially sensitivity to the thermal photon noise at room temperature, an alternative optoelectronic system is designed to address the problem. We study a method by which it may be possible to remove the mechanical part of the previous systems to minimize the thermally generated photons. Unlike optomechanical systems, in our system, the optical mode is directly coupled to the microwave cavity mode through the optoelectronic elements without employing any mechanical parts. The utilized approach leads to generating the entangled modes at room temperature. For this purpose, the dynamics of the motion of the optoelectronic system is theoretically derived using the Heisenberg-Langevin equations from which one can calculate the coupling between optical and microwave cavity modes. The direct coupling between the optical and microwave cavity modes is the most important feature and is achieved through the combination of the photodetector and a Varactor diode. Hence, by controlling the photodetector current, that is, the photocurrent, depending on the optical cavity incident wave and the Varactor diode-biased voltage, the coupling between the optical and microwave cavity modes is established. The voltage across the Varactor diode also depends on the generated photocurrent. Consequently, our results show that the coupled modes are entangled at room temperature without the requirement for any mechanical parts.
Citation - WoS: 16
Citation - Scopus: 16
Entanglement Sustainability Improvement Using Optoelectronic Converter in Quantum Radar (Interferometric Object-Sensing)
(Ieee-inst Electrical Electronics Engineers inc, 2021) Salmanogli, Ahmad; Gokcen, Dincer
In this study, the main focus is laid on the design of an optoelectronic converter as a part of the quantum radar to enhance the entanglement between retained and returned modes at high temperatures. The electro-opto-mechanical converter has been widely studied, and the results showed that the operation at high temperature is so crucial to generate and preserve the entanglement between modes. The main problem arises because the mechanical part operating at a low frequency leads to a large number of thermally excited photons, and eventually, the entanglement between modes becomes lost. To solve the problem, we replace the mechanical part with the optoelectronic components. The optical cavity is coupled to the microwave cavity in the newly designed system through a Varactor diode excited by a photodetector. As the main goal, to improve the entanglement sustainability, the effect of the coupling factor of the microwave cavity to photodetector is investigated. The results show that the mentioned factor creates some degrees of freedom to enhance the entanglement at high temperatures compared to the electro-opto-mechanical converter. At some specific values of the coupling factor, the retained and returned fields remained completely entangled up to 5.5 K and partially entangled around 50 K.
Citation - WoS: 3
Identification of Circulating Tumor Cells Using Plasmonic Resonance Effect: Lab-on-a- Chip Analysis and Modelling
(Amer Scientific Publishers, 2020) Salmanogli, Ahmad; Gokcen, Dincer; 280089
Circulating tumor cells are widely used as biomarkers of cancer. Although early detection of these cells is vital for diagnosis and prognosis of deadly cancer, it is still a challenging issue due to the complex matrix of blood and their low presence in the bloodstream. In the present study, we propose a micro-channeled lab-on-a-chip system using two distinct methods based upon dielectrophoretic force and electrical properties of cells to increase the cell detection capability and identification efficiency and accuracy. The dielectric properties of cells contribute to the difference between negatively charged residues on the cell surface. Firstly, the dielectrophoretic force is used to separate background cells; then, the proposed high-accuracy identification method is used to better examine and study the unidentified cells. In the next phase, by amplification of the current of the unidentified cells flowing through the nanoparticle plasmonic resonance effects, the microfluidics output efficiency is significantly improved. As a result, highly accurate cell identification is achieved by taking advantage of the nanoparticle plasmonic properties. Overall, nanoparticle scattering in the plasmonic resonance condition, as well as their plasmonic hybridization, can improve output signal-to-noise ratio.
Citation - WoS: 5
Citation - Scopus: 5
Plasmonic Effect on Quantum-Dot Photodetector Responsivity
(Ieee-inst Electrical Electronics Engineers inc, 2019) Salmanogli, Ahmad; Gokcen, Dincer; Gecim, H. Selcuk; 280089; 182579
In this paper, we analyze and simulate the plasmonic effect on the quantum-dot photodetector responsivity. For this purpose, a plasmonic-based quantum-dot photodetector is designed in which a few quantum dots are embedded in the hot-spot regions of the plasmonic nanoparticles, wherein a high-intensity localized field is created. Notably, due to the maximum overlapping of the plasmonic field with the quantum dots at the hot spot, some of the optical characteristics of the quantum dot, particularly the spontaneous emission decay rate, are changed. This paper focuses on the engineering of the decay rate, through which we found that the quantum-dot photodetector responsivity is strongly enhanced with the order of 100 times at the visible range. For analyzing the proposed system, we first work on the plasmonic effect of the nanoparticle on the quantum-dot lifetime using the Heisenberg-Langevin equations. It is shown that by embedding the quantum dots at the hot spot of the nanoparticle, the decay rate of the quantum dot is dramatically influenced. In the following, plasmonic-quantum dot system responsivity is theoretically examined using a time-varying perturbation theory. Using this approach is necessary because the spontaneous emission cannot be analyzed with the classical methods. Consequently, it is proved that using plasmonic effect leads to enhanced photodetector responsivity, suggesting that even very small incoming signals are detectable.