Elektronik ve Haberleşme Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/260
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Conference Object Diffraction of Matter Waves in Time by an Absorbing Half-Screen(2010) Umul, Y.Z.; Umul, Yusuf Ziya; Elektronik ve Haberleşme MühendisliğiIn this study, the scattering of matter waves that accompany to the quantum particles by an absorbing half-plane is examined. A quantum shutter, which is opened at an initial time, is proposed to close the semi-infinite complementary aperture of the half-screen. Hence the matter waves, confined in a determined region of space, transmits to the second region by scattering from the semi-infinite aperture. The mathematical expressions of the scattered fields are plotted numerically and interpreted according to the diffraction theory of Young.Book Review Citation - WoS: 4Citation - Scopus: 5The Theory of the Boundary Diffraction Wave(Elsevier Academic Press inc, 2011) Umul, Yusuf ZiyaArticle Citation - WoS: 1Citation - Scopus: 2Wave Diffraction by a Thin Lossy Dielectric Half-Plane(Elsevier Gmbh, 2021) Umul, Yusuf ZiyaThe scattering of electromagnetic waves by a thin lossy dielectric half-plane is investigated. With this aim, the interaction process of waves with a dielectric layer is studied. The reflection and transmission coefficients are obtained in the limiting case, which is defined when the thickness of the layer is sufficiently smaller than the wavelength. The diffracted waves by the half-plane are evaluated using the method of transition boundary. Some numerical results are given. We will study the interaction problem of electromagnetic waves by a thin lossy dielectric half-plane in this paper. It will be supposed that the width of the dielectric layer is sufficiently smaller than the wavelength of the incident field. In the literature, such a structure is modeled by the resistive boundary conditions [1]. The scattering of waves by a resistive half-plane has been investigated in the literature by some authors [2-9]. Rawlins [10] solved the diffraction problem of plane waves by a thin dielectric half-screen by using approximate boundary conditions. Anderson [11] studied the same scenario and obtained a solution with the method of dual integral equation. A Wiener-Hopf approach was applied by Chakrabarti [12] to the dielectric half-plane, illuminated by a plane electromagnetic wave. Senior and Volakis [13] derived approximate boundary conditions for a thin dielectric layer and applied them to the diffraction problem, under consideration, for magnetic polarization [14]. We will take into consideration a lossy dielectric layer with finite width d and derive the reflected and transmitted electromagneticArticle Citation - WoS: 1Citation - Scopus: 1Wave Diffraction by a Perfect Magnetic Conductor Half-Plane Between Free Space and Anisotropic Plasma(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe diffraction of magnetic polarized electromagnetic plane waves by a perfect magnetic conductor half-screen, located between free space and anisotropic plasma, is studied. The method of transition boundary is used for the solution of the problem. The scattered GO wave is obtained. The diffracted fields are derived with the aid of the scattered GO wave. The uniform expressions of the edge diffracted waves are derived. The behaviors of the evaluated fields are investigated numerically.Article The Standing Matter Waves and Bohm's Quantum Potential(Elsevier Gmbh, 2021) Umul, Yusuf ZiyaThe standing wave type wave functions are investigated in terms of Bohm's decomposition of the Schro spacing diaeresis dinger equation. It is shown that the quantum potential, obtained for the standing matter waves, is always different from zero. However, it is also put forth that the wave function do not satisfy the Bohm's equations except one case, which is defined in the Cartesian coordinates. The Airy type matter wave is also analyzed in terms of the Bohmian approach.Article Citation - WoS: 2Citation - Scopus: 8Scattering of Electromagnetic Waves by an Impedance Sheet Junction in Anisotropic Plasma(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe diffraction of electromagnetic plane waves by the edge discontinuity of an impedance sheet junction, which is located in an anisotropic plasma, is investigated. The problem is solved by the integral theory of diffraction. The scattering integral is obtained from the scattered geometric optics wave. The diffracted fields are derived by the edge point evaluation of the scattering integral. The evaluated field expressions are analyzed numerically.Article Propagation and Diffraction of Surface Plasmons on a Resistive Half-Plane(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe propagation, radiation and diffraction characteristics of surface plasmons, on a discontinuous dielectric layer, are investigated. The layer is modeled by a resistive surface. The physical optics based formulation of the surface waves is taken into account. The physical optics integral includes the propagating and diffracting fields. These wave components are evaluated asymptotically and their behaviors are studied numerically.Article Citation - WoS: 1Citation - Scopus: 2Physical Optics Approach To Wave Diffraction by a Perfect Electromagnetic Conductor Half-Plane(Springer, 2021) Umul, Yusuf ZiyaThe scattering of electromagnetic plane waves by a perfect electromagnetic conductor is investigated. The method of physical optics is used for the analysis of the problem. The reflected fields by a whole-plane are taken into account. The surface electric and magnetic current densities are constructed with the aid of the incident wave and the reflected field from the whole-surface. The scattering integrals are obtained for the electric and magnetic vector potentials. The scattered electric and magnetic fields are expressed in terms of the vector potentials. The scattering integrals are evaluated asymptotically for large values of the wave-number. Some numerical results are given.Article Citation - WoS: 3Citation - Scopus: 5On the Reality of the Bohmian Potential(Elsevier Gmbh, 2020) Umul, Yusuf ZiyaThe existence of the Bohmian quantum potential is investigated in terms of the energy relation of a quantum particle. The derivation process of the quantum potential is applied to the Helmholtz equation and it is shown that a similar term also occurs in this case. The possibility of the existence of a potential term is questioned according to the frequency and wave-number quantities of a wave which is the solution of the Helmholtz equation. By using the same approach, it is shown that the quantum potential should be equal to zero. Some examples are studied in terms of the wave function.Article Citation - WoS: 2Citation - Scopus: 3Diffraction in Time of an Entangled Non-Relativistic Quantum Particle(Iop Publishing Ltd, 2021) Umul, Yusuf ZiyaThe diffraction process of an entangled non-relativistic quantum particle in time domain is investigated. The scenario consists of two entangled spin-0 particles and a quantum shutter, which is opened at an initial time. The particles are traveling in two opposite sides and expressed with a single wave function. The integral solution of the Schrodinger equation is considered for two particles case. The initial condition is expressed in terms of an entangled wave function. The time-diffracted matter wave is obtained in terms of the Fresnel integral. The effect of the phenomenon of diffraction in time is examined numerically for the entangled system of two particles.