Publication Date: 2016
Plasmonics (15571963)11(3)pp. 875-884
In this paper, we will present a quantization method for surface plasmon polariton (SPP) based on Green’s tensor method, which is applied usually for quantization of EM field in various dielectric media. This method will be applied for a semi-infinite structure, which contains metal and dielectric regions with one interface. Moreover, by introducing the quantized SPP, we will investigate the SPP propagation in the attenuating and amplifying systems. We will also consider two modes of SPP, i.e., coherent and squeezed states, and finally compare the propagation of these modes in the amplifying media. © 2015, Springer Science+Business Media New York.
Publication Date: 2016
Journal of Physics B: Atomic, Molecular and Optical Physics (09534075)49(6)
Using two different schemes, a non-classical-squeezed state of light is detected and characterized. In the first scheme, in a one-dimensional cavity with a moving mirror (non-stationary Casimir effect) in the principal mode, we study the photon generation rate for two modes (squeezed and coherent state) of a driving field. Since the cavity with the moving mirror (similar to an optomechanical system) can be considered an analogue to a Kerr-like medium, in the second scheme, the probability amplitude for multi-photon absorption in a nonlinear (Kerr) medium will be quantum mechanically calculated. It is shown that because of the presence of nonlinear effects, the responses of these two systems to the squeezed versus coherent state are considerably distinguishable. The drastic difference between the results of these two states of light can be viewed as a proposal for detecting non-classical states. © 2016 IOP Publishing Ltd.
Publication Date: 2016
International Journal of Theoretical Physics (15729575)55(1)pp. 124-136
In this paper, we study the quantum free particle on the spherical space by applying da costa approach for quantum particle on the curved space. We obtain the discrete energy eigenvalues and associated normalized eigenfunctions of the free particle on the sphere. In addition, we introduce the Gazeau-Klauder coherent states of free particle on the sphere. Then, the Gaussian coherent states is defined, which is used to describe the localized particle on the spherical space. Finally, we study the relation between the f-deformed coherent states and Gazeau-Klauder ones for this system. © 2015, Springer Science+Business Media New York.
Publication Date: 2016
Progress in Electromagnetics Research M (19378726)49pp. 117-129
An optical impedance-matched medium with a gradient refractive index can resemble a geometrical analogy with an arbitrary curved space-time. In this paper, we show that a non-impedancematched medium with a varying optical axis can also resemble the features of a space of non-trivial metric for the light. The medium with a varying optical axis is an engineered stratified slab of material, in which the orientation of the optical axis in each layer slightly differs from the other layers, while the magnitude of refractive index remains constant. Instead of the change in refractive index, the inhomogeneity of such a medium is induced by the local anisotropy. Therefore, the propagation of light depends on the local optical axis. We study the conditions that make the analogy between curved spacetime and a medium with a varying optical axis. Extension of the transformation optics to the media with optical axis profile might ease some fabrication difficulties of materials with gradient refractive index. © 2016, Electromagnetics Academy. All rights reserved.
Publication Date: 2015
Quantum Information Processing (15700755)14(8)pp. 2895-2907
In this paper, we investigate the behavior of radiation field, whose state is described by the so-called sphere coherent state, through a beam splitter. These states are realization of coherent states of two-dimensional harmonic oscillator, which lives on a sphere, as radiation field. By using the linear entropy as a measure of entanglement, we show that the entanglement depends on the curvature of the sphere. So, by using the appropriating sphere coherent states, we can control the entanglement of the output states of the beam splitter in the laboratory. In addition, as the convince measures of non-classical behaviors, we consider Mandel parameters of the output states of the beam splitter and their quadrature squeezing. © 2015, Springer Science+Business Media New York.
Publication Date: 2015
Foundations of Physics (15729516)45(7)pp. 827-839
In this work we present a construction of coherent states based on ”complexifier” method for a special type of one dimensional nonlinear harmonic oscillator presented by Mathews and Lakshmanan (Q Appl Math 32:215, 1974). We will show the state quantization by using coherent states, or to build the Hilbert space according to a classical phase space, is equivalent to departure from real coordinates to complex ones. © 2015, Springer Science+Business Media New York.
Publication Date: 2015
Quantum Information Processing (15700755)14(2)pp. 593-606
In this paper, we suggest a scheme which can produce various types of entangled states of the cavity field. In the scheme, cavities with different circumstances which evolve in time are utilized. It is shown that if two cavities are arranged in a way that, the first cavity is governed by the Jaynes–Cummings (JC) and the other with anti-Jaynes–Cummings (anti-JC) Hamiltonian, entangled EPR state of the cavity field is generated. Also, the proposal can be extended to the multi-cavity case, where the cavities are arranged such that their time evolutions change alternately from JC to anti-JC Hamiltonian. From this configuration, three- and four-partite GHZ states can be generated. At last, it is illustrated that in the multi-cavity set up if one prepares all cavities with the same time evolution property, W state can be produced. An important feature of this scheme is the fact that the result of the processes is independent of the result of atomic detection. © 2014, Springer Science+Business Media New York.
Publication Date: 2014
Modern Physics Letters A (02177323)29(19)
We study the two-dimensional harmonic oscillator on a noncommutative plane. We show that by introducing appropriate Bopp shifts, one can obtain the Hamiltonian of a two-dimensional harmonic oscillator on a sphere according to the Higgs model. By calculating the commutation relations, we show that this noncommutativity is strictly dependent on the curvature of the background space. In other words, we introduce a kind of duality between noncommutativity and curvature by introducing noncommutativity parameters as functions of curvature. Also, it is shown that the physical realization of such model is a charged harmonic oscillator in the presence of electromagnetic field. © 2014 World Scientific Publishing Company.
Publication Date: 2014
Journal of the Optical Society of America B: Optical Physics (07403224)31(2)pp. 270-276
The proposed schemes in this paper involve the interaction of a two-level atom with single- or two-mode quantized cavity fields (for different purposes) in the presence of a classical field. Indeed, following the path of Solano et al. in [Phys. Rev. Lett. 90, 027903 (2003)], the behavior of the entire atom-field system may be described by the Jaynes-Cummings (JC)- and anti-Jaynes-Cummings (anti-JC)-like models. It is illustrated that, under specific conditions, the effective Hamiltonian of the system can be switched from a JC- to an anti-JC-like model. During the process, the two-level atom in the cavity is alternately affected by the above two effective interactions. Ultimately, after the occurrence of the desired interactions in appropriate setups, the cavity field will arrive at a specific superposition of number states, a fixed number state, and in particular, two-mode binomial field states. Moreover, the entanglement property of the two-mode binomial state is investigated by evaluating the entropy criterion. While there exist various proposals for preparation of number states and their superpositions in the literature, our scheme has the advantage that it is independent of the detection of the atomic state after the interaction occurs. © 2014 Optical Society of America.
Publication Date: 2013
International Journal of Geometric Methods in Modern Physics (17936977)10(10)
Three methods: complexifier, factorization and deformation, for construction of coherent states are presented for one-dimensional nonlinear harmonic oscillator (1D NLHO). Since by exploring the Jacobi polynomials P na,b,s, bridging the difference between them is possible, we give here also the exact solution of Schrödinger equation of 1D NLHO in terms of Jacobi polynomials. © World Scientific Publishing Company.
Publication Date: 2013
International Journal of Geometric Methods in Modern Physics (17936977)10(5)
At first, we introduce -deformed algebra as a kind of generalization of the Weyl-Heisenberg algebra so that we get the su(2)-and su(1, 1)-algebras whenever has specific values. After that, we construct coherent states of this algebra. Third, a realization of this algebra is given in the system of a harmonic oscillator confined at the center of a potential well. Then, we introduce two-boson realization of the -deformed Weyl-Heisenberg algebra and use this representation to write -deformed coherent states in terms of the two modes number states. Following these points, we consider mean number of excitations (we call them in general photons) and Mandel parameter as statistical properties of the -deformed coherent states. Finally, the Fubini-Study metric is calculated for the -coherent states manifold. © 2013 World Scientific Publishing Company.
Publication Date: 2013
Journal of Modern Optics (13623044)60(3)pp. 233-239
In this paper, to obtain an analogy between the curved spaces and the linear optics, we expand the idea of Sánchez-Soto and co-workers [Phys. Rep. 2012, 513, 191; Phys. Rev. A 2011, 84, 023830] to the multilayer films. We investigate effects of thickness and index of refraction of the films on the Lorentzian transformations. In addition, by using the multilayer films, we suggest a very simple experimental set-up which can serve as an analogue computer for testing special relativity. Finally, we draw an analogy between the Rindler space, as an example of the curved spaces, and a suitable multilayer film. Copyright © 2013 Taylor & Francis.
Publication Date: 2012
AIP Conference Proceedings (0094243X)1508pp. 474-477
Generalized f-coherent state approach in deformation quantization framework is investigated by using a *-eigenvalue equation. For this purpose we introduce a new Moyal star product called f-star product, so that by using this *f-eigenvalue equation one can obtain exactly the spectrum of a general Hamiltonian of a deformed system. © 2012 American Institute of Physics.
Publication Date: 2012
Journal of Physics A: Mathematical and Theoretical (17518113)45(46)
In this paper, we investigate a two-dimensional isotropic harmonic oscillator on a time-dependent spherical background. The effect of the background can be represented as a minimally coupled field to the oscillator's Hamiltonian. For a fluctuating background, transition probabilities per unit time are obtained. Transitions are possible if the energy eigenvalues of the oscillator E i and frequencies of the fluctuating background ω n satisfy the following two simple relations: E j≃E i ω n (stimulated emission) and E j≃E i + h d ω n (absorption). This indicates that a background fluctuating at a frequency of ω n interacts with the oscillator as a quantum field of the same frequency. We believe this result is also applicable for an arbitrary quantum system defined on a fluctuating maximally symmetric background. © 2012 IOP Publishing Ltd.
Publication Date: 2011
Physica A: Statistical Mechanics and its Applications (03784371)390(7)pp. 1381-1392
In this paper, the generalized coherent state for quantum systems with degenerate spectra is introduced. Then, the nonclassicality features and number-phase entropic uncertainty relation of two particular degenerate quantum systems are studied. Finally, using the GazeauKlauder coherent states approach, the time evolution of some of the nonclassical properties of the coherent states corresponding to the considered physical systems are discussed. © 2010 Elsevier B.V. All rights reserved.
Publication Date: 2011
Journal of Physics A: Mathematical and Theoretical (17518113)44(8)
Based on the definition of coherent states for continuous spectra and analogous to photon-added coherent states for discrete spectra, we introduce the excited coherent states for continuous spectra. It is shown that the main axioms of Gazeau-Klauder coherent states will be satisfied, properly. Nonclassical properties and quantum statistics of coherent states, as well as the introduced excited coherent states, are discussed. In particular, through the study of quadrature squeezing and amplitude-squared squeezing, it will be observed that both classes of the above states can be classified in the intelligent states category. © 2011 IOP Publishing Ltd.
Publication Date: 2005
Journal of Mathematical Physics (10897658)46(4)
Using the analytic representation of the so-called Gazeau-Klauder coherent states (CSs), we shall demonstrate that how a new class of generalized CSs, namely the family of dual states associated with theses states, can be constructed through viewing these states as temporally stable nonlinear CSs. Also we find that the ladder operators, as well as the displacement type operator corresponding to these two pairs of generalized CSs, may be easily obtained using our formalism, without employing the supersymmetric quantum mechanics (SUSYQM) techniques. Then, we have applied this method to some physical systems with known spectrum, such as Pöschl-Teller, infinite well, Morse potential and hydrogenlike spectrum as some quantum mechanical systems. Finally, we propose the generalized form of the Gazeau-Klauder CS and the corresponding dual family. © 2005 American Institute of Physics.
Publication Date: 2004
Journal of Physics A: Mathematical and General (03054470)37(33)pp. 8111-8127
Considering some important classes of generalized coherent states known in the literature, we demonstrated that all of them can be created via conventional methods, i.e. the 'lowering operator eigenstate' and the 'displacement operator' techniques using the 'nonlinear coherent states' approach. As a result we obtained a 'unified method' to construct a large class of coherent states which have already been introduced by different prescriptions.
Publication Date: 2004
Journal of Physics A: Mathematical and General (03054470)37(21)pp. 5649-5660
We establish some of the properties of the states interpolating between number and coherent states denoted by |n〈λ; among them are the reproduction of these states by the action of an operator-valued function on |n〈 (the standard Fock space) and the fact that they can be regarded as f -deformed coherent bound states. In this paper we use them as the basis of our new Fock space which in this case is not orthogonal but normalized. Then by some special superposition of them we obtain new representations for coherent and squeezed states in the new basis. Finally the statistical properties of these states are studied in detail.
Publication Date: 2004
Journal of Physics A: Mathematical and General (03054470)37(15)pp. 4407-4422
Starting with the canonical coherent states, we demonstrate that all the so-called nonlinear coherent states, used in the physical literature, as well as large classes of other generalized coherent states, can be obtained by changes of bases in the underlying Hubert space. This observation leads to an interesting duality between pairs of generalized coherent states, bringing into play a Gelfand triple of (rigged) Hubert spaces. Moreover, it is shown that in each dual pair of families of nonlinear coherent states, at least one family is related to a (generally) non-unitary projective representation of the Weyl-Heisenberg group, which can then be thought of as characterizing the dual pair.
Publication Date: 2025
Nanoscale (20403372)17(9)pp. 5403-5412
Silver-silver iodide (Ag-AgI) films are photosensitive materials in the visible light region. In this work, the colour change in Ag-AgI films under low-power monochromatic laser irradiation is shown, which is due to the size variation of silver nanoparticles (AgNPs) on the AgI thin films. This colour variation depends on the wavelength of the laser beam. In contrast, it is independent of the silver iodide thickness. Laser irradiation is employed not only for the colouration of Ag-AgI films but also for promoting the crystallinity of Ag and AgI in these films. At room temperature and atmospheric pressure, the β-phase and the γ-phase of AgI crystals are formed. The optical and structural changes of the Ag-AgI films with two different thicknesses of silver iodide, before and after laser irradiation, are characterized by synchrotron X-ray diffraction, UV-vis spectrophotometry, and X-ray photoelectron spectroscopy. The growth of silver crystals after laser irradiation is significant, especially in the sample with a thinner AgI film under the irradiation of green and blue laser beams with an energy higher than the bandgap energy. However, in the sample with a thicker film of AgI, the size of the β-phase and the γ-phase of AgI crystals increases faster than that of silver crystals after laser irradiation. This study demonstrated that Ag-AgI films have antibacterial and photocatalytic activities. © 2025 The Royal Society of Chemistry.
Publication Date: 2024
Optics and Laser Technology (00303992)171
Holographic silver nanogratings on the surface and within the volume, which have significant potential for data storage applications, are generated in silver chloride (AgCl) waveguides using a single laser beam exposure. This formation process leverages the interference between the polarized incident wave and the TEm modes propagating inside the AgCl waveguide. These plasmonic nanogratings are anisotropic nanostructures, demonstrating intriguing optical traits such as wavelength-specific linear dichroism and birefringence. The observed linear dichroism and birefringence in the holographic silver nanograting can modify the optical rotation and ellipticity of a probe beam traversing this anisotropic medium. Notably, volume holographic nanogratings function as complex nanogratings with a periodicity exceeding that of the incident wavelength. As a result, upon exposure, these complex nanogratings exhibit discernible light diffraction, while the surface holographic nanogratings do not show any diffraction pattern. Additionally, as the AgCl film thickness is increased and more complex nanogratings are formed within the AgCl waveguides, there is a noted reduction in the resulting birefringence. © 2023 Elsevier Ltd
Publication Date: 2022
Iranian Journal of Physics Research (16826957)22(1)pp. 99-111
In this research, the effect of exposure time on the phenomenon of multicolor photochromism in silver-silver chloride thin film has been investigated. The effect of multicolor photochromism in the silver-silver chloride layer is created by continuous-beam laser radiation in a short time. Irradiating the subwavelength silver-silver chloride layer by monochromatic and linear polarized laser beam in the visible light region, creates multicolor photochromism phenomenon and induced anisotropy simultaneously. Anisotropy in these layers is due to the alignment of silver nanoparticles along the polarization of light; whereas multicolor photochromism due to the resizing of silver nanoparticles is proportional to the wavelength of the incident light. An interesting phenomenon in silver-silver chloride thin films is the possibility of removing both effects by ultraviolet radiation. Also, in this study, we showed that although the phenomenon of multicolor photochromism is caused by laser writing in a short time, the complete removal of this effect by irradiation of ultraviolet light is not instantaneous and is done over time. Therefore, the use of silver-silver chloride thin films is not only useful for multiple color printing, it also has the potential to be used for dosimetry of ultraviolet light. © 2022, Isfahan University of Technology. All rights reserved.
Publication Date: 2022
ACS Applied Nano Materials (25740970)5(4)pp. 5439-5447
We report the fabrication and properties of ion-exchanged optical waveguides based on low-cost soda-lime glasses embedded with silver ions and nanoparticles. Using the thermal ion-exchange process, we embed silver ions into soda-lime glasses by covering the glasses with different ratios of AgNO3:NaNO3 molten salt (2:98, 4:96, and 6:94) at 350 °C. The ion-exchanged glasses containing silver nanoparticles were characterized by using X-ray fluorescence spectroscopy, UV-visible spectroscopy, the X-ray diffraction technique, X-ray photoelectron spectroscopy, and atomic force microscopy of the surface. It is shown that the ion-exchanged glasses make low-loss optical waveguides. Furthermore, we evaluate the refractive index of ion-exchanged waveguides by laser coupling into the waveguide. For this purpose, the ion-exchanged glasses were coated with a silver chloride thin film loaded with silver nanoparticles (Ag-AgCl). When the Ag-AgCl layer is irradiated by a polarized coherent light beam, silver nanograting is formed on the surface of the ion-exchanged glass, and the light beam is simultaneously coupled into the glass. The line-space of nanograting determines the effective refractive index of the ion-exchanged glass. Although we expected the sample with the highest ratio of AgNO3:NaNO3 salt (6:94) to have the largest refractive index, our results demonstrate that the ion-exchanged sample with 4% AgNO3 has the largest effective refractive index, which is due to the penetration of more silver ions and nanoparticles in the glass matrix. Therefore, it is further demonstrated that using a Ag-AgCl layer on an ion-exchanged waveguide is an effective method for coupling light into the waveguides and measuring its refractive index. The mentioned coupling technique in combination with easily fabricated ion-exchanged waveguide has served as an excellent platform for applications in integrated optical circuits. © 2022 American Chemical Society.
Talebi, R.,
Ditlbacher, H.,
Krenn, J.R.,
Hohenau, A. Publication Date: 2021
Journal of Physical Chemistry C (19327447)125(4)pp. 2519-2523
Silver iodide (AgI) is an efficient blue emitter that is easily synthesized and nanostructured. We investigate the coupling of AgI to plasmon modes, choosing aluminum (Al) owing to its low damping in the blue spectral range, in contrast to silver or gold. We investigate, first, an extended Al thin film overcoated with a SiO2 spacer layer and a AgI film. Spectroscopic surface plasmon resonance measurements confirm the anticrossing in the system's dispersion diagram, with a large energy splitting of about 140 meV, indicative of the onset of strong coupling. Second, we probe Al nanodisks overcoated with SiO2 and AgI, spectrally shifting the dipolar Al plasmon over the AgI absorption line by lithographically controlling the disk diameter. From extinction spectra, we again observe anticrossing, with an energy splitting of about 100 meV. Our results demonstrate that AgI is an easily fabricated and structured emitter, which in combination with Al forms an attractive platform to achieve an efficient plasmon-exciton coupling in the blue spectral range. © 2021 American Chemical Society.
Publication Date: 2020
Journal of the Optical Society of America B: Optical Physics (07403224)37(10)pp. 2848-2855
Silver nanogratings are anisotropic plasmonic nanostructures with potential application in optical components due to their large birefringence and dichroism. We induced linear birefringence and linear dichroism in subwavelength Ag-AgCl films by irradiating with a single low-power linearly polarized laser beam. The laser beam aligns silver nanoparticles in the direction of laser polarization and forms nanograting. We used Stokes parameters to determine linear birefringence and linear dichroism in silver aligned nanostructures. The values of linear dichroism and linear birefringence in silver nanogratings are controllable through manipulating the spatial period of nanogratings. The dispersion characteristic of dichroism and birefringence is also investigated. © 2020 Optical Society of America
