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Journal of Cosmology and Astroparticle Physics (14757516)2025(5)
In this paper, we develop a quantum field theory framework to describe the interaction between a gravitational wave (GW) background and an electromagnetic (EM) field emitted from a distant celestial source, such as a star. We demonstrate that a background of primordial gravitational waves (PGWs), as predicted by the inflationary scenario, induces a loss of spatial coherence in the EM field as it propagates over cosmological distances. This effect leads to the degradation of van Cittert-Zernike correlations, ultimately rendering them unobservable — a phenomenon referred to as blurring. Since spatial coherence is observed in very long baseline interferometry (VLBI) measurements of distant quasars, this places constraints on the amplitude of the PGW background. We quantitatively evaluate the blurring effect caused by PGWs in a two-mode squeezed state, which represents the standard quantum state predicted by the simplest inflationary models. However, due to the weak coupling between GWs and the EM field, we find that the induced incoherence is too small to be detected in current VLBI observations. © 2025 IOP Publishing Ltd and Sissa Medialab. All rights, including for text and data mining, AI training, and similar technologies, are reserved.
Physical Review A (24699934)110(1)
Entanglement formation between the magnons as the internal degrees of freedom and the center-of-mass motion (CM) as the external degrees of freedom of a levitated yttrium iron garnet (YIG) sphere in a cavity-magnomechanical system is studied. Here, we propose a scheme for generating magnon-CM entanglement independent from the mass and size of the sphere in the hybrid magnonic system by driving the magnon with the parametric amplification. First, we show that the power and frequency of the driving field significantly affect this entanglement, since the driving field increases effective magnon-CM coupling. But, by increasing the magnon damping rate, this entanglement considerably decreases. Moreover, in the next step, we demonstrate the manipulation and enhancement of this entanglement by driving the magnon into the squeezed state. Our results present an approach for preparing quantum states and may find promising applications in the quantum metrology and sensing. © 2024 American Physical Society.
Journal of Physics B: Atomic, Molecular and Optical Physics (09534075)56(23)
In this work, we consider a parity-time ( P T ) symmetric cavity magnonic system involving the magnon-photon interaction with small magnon Kerr nonlinearity. Moreover, we investigate the effect of P T -symmetry phase on both the magnon and photon blockade. We show that the P T -symmetry phase, which is achievable by properly selecting the system parameters, can relax the large Kerr nonlinearity requirement for magnon blockade. Consequently, simultaneous perfect magnon and photon blockade can be easily obtained even in the presence of a small value of magnon Kerr nonlinearity. The outstanding feature of the selected scheme is the occurrence of simultaneous perfect magnon and photon blockade with only a small value of magnon Kerr nonlinearity. While photon blockade can be easily distinguished experimentally, the experimental realization of magnon statistics and consequently magnon blockade is still a challenge. The prominent feature of the P T -symmetric cavity magnonic system can relax this challenge by following the magnon blockade criteria via the photon statistics. © 2023 IOP Publishing Ltd.
Physica Scripta (00318949)98(5)
Based on optical medium analogy, we establish a formalism to describe the interaction between an electromagnetic (EM) system with gravitational waves (GWs) background. After a full discussion on the classical treatment of the EM-GW interaction and finding the EM field mode-functions in the presence of the magneto-dielectric media caused by GWs, the governing quantum interaction Hamiltonian is obtained. Investigation of the optical quadrature variance as well as the visibility of a laser field interacting with the multi-mode squeezed primordial gravitational waves imply that the inflationary primordial gravitational waves (PGWs) act as a decoherence mechanism that destroy EM coherency after a characteristic time scale, τ c , which depends on the inflationary parameters (β, β s , r), or equivalently, the fractional energy density of PGWs, Ω gw,0. The decoherency mechanism overcomes the coherent effects, such as revivals of optical squeezing, thus leaving their confirmation out of reach. Influenced by the continuum of the squeezed PGWs, the laser field suffers a line-width broadening by γ = τ c − 1 . The most peculiar property of the EM spectrum is the apparition of side bands at ω ∼ ω 0 ± 1.39 τ c − 1 Hz, stemming from the squeezed nature of PGWs. The laser phase noise induced by the squeezed PGWs grows with time squarely, Δ ϕ = t / τ c 2 , that can most possibly be sensed within a finite flight time. © 2023 IOP Publishing Ltd
Al-hamaidah, A.,
Roknabadi, M.R.,
Bagheri harouni, M.,
Malaekeh-nikouei, B.,
Mahmoudi, A.,
Ghanbari, R.,
Charmforoushan, A. Materials Chemistry and Physics (02540584)306
Herein, we report the synthesis of a mesoporous calcium silicate superparamagnetic nanoparticle as ZnMnFe2O4@Fe–CaSiO3 core-shell. This core-shell nanocomposite reveals excellent properties such as mesoporous nanocomposite, superparamagnetic at room temperature, low toxicity, large surface area, tunable pore size, and easy surface manipulation. The core nanocomposite (ZnMnFe2O4) is synthesized by the hydrothermal method, which shows a superparamagnetic behavior with an excellent saturation magnetization of 52.09 emu/g. The core-shell structure is prepared by a micellar-assisted sol-gel method, which uses a copolymer to create pores in the structure of CaSiO3. To improve the magnetic properties of the core-shell structure, different percent of Fe ions (0%, 5%, and 10%) are doped onto the calcium silicate structure; as for 10% Fe, i.e., ZnMnFe2O4@Fe10–CaSiO3, saturation magnetization and coercive magnetic field are 34.543 emu/g and 1Oe, respectively. In this configuration of nanocomposite, the pore volume and superparamagnetic property increase simultaneously. In addition, the core-shell mesoporous ZnMnFe2O4@Fe–CaSiO3 nanocomposite reveals comparable mesoporous channels (3.4–6 nm), while the amorphous structure of CaSiO3 has not been changed. These core-shell mesoporous superparamagnetic nanocomposites are evaluated in terms of drug loading and release using epirubicin (EPI) as a model drug. It is found that the increase of iron ions improves the capacity to stabilize the pH environment. Additionally, the mesoporous Fe–CaSiO3 nanostructures demonstrate a sustained drug release property that could be used in local drug delivery therapy. Therefore, these mesoporous superparamagnetic nanostructures would be a promising multifunctional platform for local drug delivery, magnetic resonance imaging, magnetic hyperthermia, and bone tissue regeneration. © 2023 Elsevier B.V.
Chinese Physics B (16741056)29(12)
Quantum speed limit time and entanglement in a system composed of coupled quantum dots are investigated. The excess electron spin in each quantum dot constitutes the physical system (qubit). Also the spin interaction is modeled through the Heisenberg model and the spins are imposed by an external magnetic field. Taking into account the spin relaxation as a non-Markovian process, the quantum speed limit and entanglement evolution are discussed. Our findings reveal that increasing the magnetic field leads to the faster quantum evolution. In addition, the temperature increment causes the longer quantum speed limit time as well as the entanglement degradation. © 2020 Chinese Physical Society and IOP Publishing Ltd.
Quantum mechanics; Quantum dot molecule; Quantum entanglement; Quantum transport; Superconductors; Josephson junction © 2020
Physical Review A (24699934)96(2)
The entanglement between photon pairs generated from the biexciton cascade transition in a semiconductor quantum dot located in the vicinity of a metal nanoparticle is theoretically investigated. In the model scheme, the biexciton-exciton and exciton-ground-state transitions are assumed to be coupled to two principal plasmon modes of orthogonal polarizations. For a broad spectral window, because the horizontal and vertical spectra overlap, the biexciton and exciton photons are degenerate in energy. This allows us to overcome the natural splitting between the intermediate exciton states. Moreover, the degree of entanglement depends on the geometrical parameters of the system, i.e., the radius of the metal nanoparticle and the distance between the quantum dot and the nanoparticle. The results reveal that such a hybrid system profoundly modifies the photon entanglement even in the absence of strong coupling between the emitter and the metal nanosphere. © 2017 American Physical Society.
Plasmonics (15571963)12(1)pp. 1-8
A theoretical study of photon statistics of an optically driven quantum dot located near a metal nanoparticle cluster (composed of one or two nanoparticles) is presented. Considering the system in the weak Rabi frequency regime, an analytical formula for anti-bunching time is derived. Using a photon Green’s function method based on the exact quantization of electromagnetic field in a dissipative medium, the dependence of the anti-bunching time on the geometrical parameters (quantum dot radius and quantum dot distance from the metal nanoparticle) is studied. The results show that these geometrical parameters have pronounced impacts on the photon statistics. Furthermore, our findings reveal that the quantum dot dipole orientation possesses an important role in the quantum dot photon emission. © 2016, Springer Science+Business Media New York.
Molecular Physics (00268976)114(14)pp. 2123-2131
ABSTRACT: The dynamics of energy transfer in Fenna–Matthews–Olson (FMO) light-harvesting complex interacting with a phonon bath is investigated. In this contribution, by considering the phonon bath as a source of stochastic noise, a new approach is proposed. Also, by calculating the global quantum entanglement and global quantum discord, the time evolution of the quantum correlation during the process is evaluated. The effects of temperature and initial excited state on the energy transfer and the quantum correlation are studied. It is shown, in agreement with the previous results, that the increasing of the temperature gives rise to the faster delocalisation of energy transfer and global quantum entanglement in the FMO complex. The proposed model predicts that the global discord is resistance versus the raising temperature. Furthermore, it is demonstrated that the quantum entanglement with respect to the global quantum discord has a significant role in the process of energy transfer in the FMO complex. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
Journal of Physics B: Atomic, Molecular and Optical Physics (09534075)49(18)
The dynamics of single-excitation energy transfer in a molecular dimer interacting with a phonon bath is studied. Although there are exact numerical solutions for this system, we propose an approach that provides exact analytical results with few electronic degrees of freedom. This approach is based on considering the phonon subsystem in the coherent state representation. Applying this approach, the long-lived coherence time is evaluated in the weak and strong coupling regimes. Moreover, by calculating the quantum entanglement and global quantum discord, the time evolution of quantum correlations is examined. The effects of two parameters, electronic coupling strength and bath temperature, on the energy transfer and quantum correlations are studied. It is shown, in agreement with previous results, that the long-lived coherence time in the weak coupling regime is longer than in the strong coupling regime. Also, the increasing bath temperature gives rise to faster delocalization of energy transfer. Furthermore, it is illustrated that the bath temperature has a significant effect on the quantum entanglement with respect to the global quantum discord. © 2016 IOP Publishing Ltd.
Laser Physics (1054660X)26(11)
We study the quantum dynamics of a nanomechanical graphene resonator. Neglecting the nonlinearities in the graphene membrane and applying a back-gate voltage, the vibrational state of the graphene membrane can be manipulated. We show that in the specific regime coherent states can be generated in the membrane. Moreover, the interaction between the vibrating graphene membrane and a Rydberg atom is investigated. This interaction originates from the Casimir-Polder interaction. Consequently, squeezed states or nonlinear coherent states may be generated in the membrane. Depending on the initial state of the graphene membrane, the membrane state may exhibit quadrature squeezing. © 2016 Astro Ltd.
Dehdashti, S.,
Bagheri harouni, M.,
Harsij z., ,
Shen j., ,
Wang h., H.,
Xu z., ,
Mirza, B.,
Chen, H. Quantum Information and Computation (15337146)16(15-16)pp. 1365-1378
We study the entanglement dynamics of two entangled spins coupled with a common environment consisting of a large number of harmonic oscillators. Specifically, we study the impacts of both interaction and temperature of the environment on the dynamic quantum correlation, namely, entanglement and quantum discord of two spins via concurrence and global quantum discord criteria. In the present system, we show that the interaction between the spin sub-systems and the common environment causes environmental states to approach a composition of even and odd coherent states, which have different phases, and which are entangled with the spin states. Moreover, using the thermofield approach, we demonstrate quantum correlation stabilization as a result of increasing environmental interaction as well as increasing temperature. © Rinton Press.
Annals of Physics (00034916)355pp. 21-34
An algebraic approach to Kepler problem in a curved space is introduced. By using this approach, the creation and annihilation operators associated to this system and their algebra are calculated. These operators satisfy a deformed Weyl-Heisenberg algebra which can be assumed as a deformed su(2) algebra. By using this fact, the nonlinear coherent states of this system are constructed. The scalar product and Bargmann representation of this family of nonlinear coherent states are constructed. The present contribution shows that these nonlinear coherent states possess some non-classical features which strongly depend on the Kepler coupling constant and space curvature. Depending on the non-classical measures, the smaller the curvature parameter, the more the non-classical features. Moreover, the stronger Kepler constant provides more non-classical features. © 2015 Elsevier Inc.
Physical Review A - Atomic, Molecular, and Optical Physics (10502947)91(2)
In this paper, we study the role of the nonlinear environment on the bound passage time of dynamical quantum spin systems, which is of great interest in quantum control and has been applied to quantum metrology, quantum computation, and quantum chemical dynamics. We consider the decoherence speed limit for the spin-deformed bosonic model and the impacts of the nonlinear environment and its temperature on the decoherence speed limit. Moreover, we show that, at an early enough time, the parameters associated with the nonlinear environment exhibit important roles in controlling the decoherence process. In addition our results reveal that, in long times, these parameters do not affect the decoherence process. © 2015 American Physical Society.
Laser Physics (1054660X)24(5)
We study the dynamics of a catlike superposition of f-deformed coherent states under dissipative decoherence. For this purpose, we investigate two important categories of f-deformed coherent states: Gazeau-Klauder and displacement-type coherent states. In addition, we consider two deformation functions; one of them describes a harmonic oscillator in an infinite well and another corresponds to a harmonic oscillator in a quantum well with finite depth. The decoherence effects appeared through a dissipative interaction of the environment with the catlike states. In this study, we first show that the Gazeau-Klauder coherent state is more resistant under the decoherence process, in contrast to the displacement-type one, and second, that the potential range of the infinite well and the depth of potential possess a remarkable role in the decoherence process. © 2014 Astro Ltd.
Quantum Information Processing (15700755)13(7)pp. 1483-1499
The entanglement behavior of Dirac field under quantum decoherence in the non-inertial frames is studied beyond the single-mode approximation. Two kinds of damping processes, amplitude damping channel and dephasing channel, are investigated as the sources of decoherence. The decoherence and Unruh effect will lead to entanglement degradation. This study demonstrates that as two observers experience the decoherence, the entanglement sudden death will occur in amplitude damping channel. Our study shows that the entanglement sudden death will occur in the presence of Unruh effect accompanying the decoherence. In addition, our results show that the amplitude damping channel has more remarkable impacts than the dephasing channel. © 2014 Springer Science+Business Media New York.
Laser Physics (1054660X)24(11)
A full quantum microscopic theory is developed to analyze a biexciton radiative cascade coupled to bulk acoustic phonons in a quantum dot. By considering the phonon sub-system in coherent state representation a new approach is proposed for investigating the phonon effects. Via this approach it is possible to obtain an exact analytical result for the phonon kernel in this system. This approach is introduced in the context of an example: the process of generating polarization-entangled photon pairs from the biexciton cascade in a quantum dot. We calculate the exact density matrix (using quantum state tomography) of photons and their concurrence. We show that the exchange interaction and temperature have remarkable effects on the degree of entanglement of the emitted photons. The approach introduced provides an exact analytical result for finite discrete electron states interacting with phonons. © 2014 Astro Ltd.
Laser Physics (1054660X)24(4)
A microscopic theory to study the combined dynamics of a quantum dot exciton coupled to a single cavity mode as well as acoustic phonons is presented. By considering the phonon subsystem in the coherent state representation, the phonon's impact on the emitted photons is investigated. The single photon emission probability and phonon effects on this quantity are studied. On the other hand, we illustrate that while a quantum dot interacts with a single cavity mode, the collapse and revival phenomenon will occur. It is demonstrated that acoustic phonons have a pronounced impact on the collapse and revival of the quantum dot exciton. Our finding reveals that at elevated temperatures the phonon interaction decreases the Rabi frequency. Moreover, the cavity mode possesses non-classical features such as sub-Poissonian statistics. © 2014 Astro Ltd.
Quantum Information Processing (15700755)13(2)pp. 527-545
The effects of Quantum decoherence on Dirac fields in an accelerated frame are studied beyond the single-mode approximation. The decoherence phenomena are investigated through the quantum channel approach using the amplitude damping channel and the dephasing one. The entanglement and purity are two distinct quantum features which are investigated. We have assumed that only the non-inertial observer experiences decoherence phenomena. The associated effects of the acceleration, damping rate, and dephasing rate are considered. It is found that acceleration and decoherence rates will decrease the degree of entanglement and purity. It turns out that beyond the single-mode approximation, the maximal entangled state cannot be achieved. Moreover, a comparison between the damping and dephasing processes is done which reveals the fact that damping effects on the entanglement are stronger than dephasing effects, whereas dephasing has stronger effects on the purity. © 2013, Springer Science+Business Media New York.
Laser Physics (1054660X)24(4)
In this paper, we study the interaction between a Λ-type three-level atom and two quantized electromagnetic fields which are simultaneously injected in a bichromatic cavity surrounded by a Kerr medium in the presence of field-field interaction (parametric down conversion) and detuning parameters. By applying a canonical transformation, the introduced model is reduced to a well-known form of the generalized Jaynes-Cummings model. Under particular initial conditions which may be prepared for the atom and the field, the time evolution of the state vector of the entire system is analytically evaluated. Then, the dynamics of the atom is studied through the evolution of the atomic population inversion. In addition, two different measures of entanglement between the tripartite system (three entities make the system: two field modes and one atom), i.e., von Neumann and linear entropy are investigated. Also, two kinds of entropic uncertainty relations, from which entropy squeezing can be obtained, are discussed. In each case, the influences of the detuning parameters and Kerr medium on the above nonclassicality features are analyzed in detail via numerical results. It is illustrated that the amount of the above-mentioned physical phenomena can be tuned by choosing the evolved parameters, appropriately. © 2014 Astro Ltd.
Journal of the Optical Society of America B: Optical Physics (07403224)30(11)pp. 2952-2959
In this paper, we consider the interaction of the nonlinear coherent states (CSs) on a sphere with a three-level atom. Since these generalized CSs depend on the curvature of the sphere, this model enables us to investigate the curvature effects of the physical space. By using the time-dependent state of the atom-field system, we first study the curvature effects on the occupation probabilities of the atomic levels. We especially study the relation between the revival time of the atomic occupation probabilities and the curvature. Then, to study the curvature effects on the dynamical properties of the cavity field, we consider photon distributions, correlation functions, and Mandel parameters of the field. The cavity field in this atom-field system exhibits nonclassical features which depend on the curvature of the physical space. © 2013 Optical Society of America.
Physics Letters, Section A: General, Atomic and Solid State Physics (03759601)377(13)pp. 952-956
The decoherence of a harmonic oscillator under two-dimensional quantum Brownian motion on a noncommutative plane is investigated. The interaction with the environment is considered by two separate models so-called coupled and uncoupled. The two-dimensional master equation and its noncommutative counterpart are derived for both employed models. The rate of the linear entropy (predictability sieve) is chosen as a criterion to investigate the purity in the presence of the space noncommutativity. Besides, a two-dimensional charged harmonic oscillator on a plane which is imposed by a perpendicular magnetic field is introduced as a realization of our model. Therefore, our approach provides a formalism to investigate the influence of the magnetic field on the decoherence of the pure states. We show that in the high magnetic field limit the rate of the decoherence will be decreased. © 2013 Elsevier B.V.
Annals of Physics (00034916)334pp. 321-333
The decoherence rate and some parameters affecting it are investigated for the generalized spin-boson model. We consider the spin-bosonic model when the bosonic environment is modeled by the deformed harmonic oscillators. We show that the state of the environment approaches a non-linear coherent state. Then, we obtain the decoherence rate of a two-level system which is in contact with a deformed bosonic environment which is either in thermal equilibrium or in the ground state. By using some recent realization of f-deformed oscillators, we show that some physical parameters strongly affect the decoherence rate of a two-level system. © 2013 Elsevier Inc.
Laser Physics (1054660X)23(11)
The interaction between a squeezed vacuum and a semiconductor quantum dot microcavity is studied. The influence of this interaction on the photon statistics, one measurable quantity, is investigated in the presence of the electron-phonon interaction. When the system interacts with the squeezed vacuum, the non-classical features of the emitted photons are studied. It turns out that the photon counting statistics depend on the detuning and temperature. The emitted photons also exhibit non-classical features such as anti-bunching, and their non-classical features depend on the degree of squeezing. Moreover, it is found that the stronger the squeezed vacuum, the weaker the non-classical features in the photon counting statistics. © 2013 Astro Ltd.
International Journal of Modern Physics A (0217751X)27(18)
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. Eventually the method is supported with some examples. © 2012 World Scientific Publishing Company.
Physical Review A - Atomic, Molecular, and Optical Physics (10502947)86(6)
We investigate a quantum-dot-based cavity system via the master-equation approach. The dynamics of the system is greatly affected by dissipation and dephasing processes. We include these phenomena to the theory through the master equation. The dissipation effects such as cavity loss, spontaneous recombination of excitons, and incoherent pumping are considered. The dephasing process is included as an electron-acoustic-phonon interaction. An intrinsic feature of solid-state cavity systems is the presence of electron-phonon interaction, which distinguishes this system from atomic cavity quantum electrodynamics. Due to the temperature dependence of phonons we use the complete form of the master equation (temperature dependence of dissipation rates) in this paper. We study the emission spectrum and photon statistics of the system. We show that cavity mode emission depends on temperature, and temperature strongly affects the photon statistics. © 2012 American Physical Society.
Annals of Physics (00034916)326(4)pp. 968-978
This paper presents a method to describe dynamics of an ion confined in a realistic finite range trap. We model this realistic potential with a solvable one and we obtain dynamical variables (raising and lowering operators) of this potential. We consider coherent interaction of this confined ion in a finite range trap and we show that its center-of-mass motion steady state is a special kind of nonlinear coherent states. Physical properties of this state and their dependence on the finite range of potential are studied. © 2010 Elsevier Inc.
Carmele, A.,
Milde, F.,
Dachner, M.,
Bagheri harouni, M.,
Roknizadeh, R.,
Richter, M.,
Knorr, A. Physical Review B - Condensed Matter and Materials Physics (10980121)81(19)
We theoretically study the polarization entanglement of photons generated by the biexciton cascade in a GaAs/InAs semiconductor quantum dot (QD) located in a nanocavity. A detailed analysis of the complex interplay between photon and carrier coherences and phonons which occurs during the cascade allows us to clearly identify the conditions under which entanglement is generated and destroyed. A quantum state tomography is evaluated for varying exciton fine-structure splittings. Also, by constructing an effective multiphonon Hamiltonian which couples the continuum of the QD-embedding wetting layer states to the quantum confined states, we investigate the relaxation of the biexciton and exciton states. This consistently introduces a temperature dependence to the cascade. Considering typical Stranski-Krastanov grown QDs for temperatures around 80 K the degree of entanglement starts to be affected by the dephasing of the exciton states and is ultimately lost above 100 K. © 2010 The American Physical Society.
Physics Letters, Section A: General, Atomic and Solid State Physics (03759601)374(40)pp. 4099-4103
A particle bounded in a potential with finite range is described by using an f-deformed quantum oscillator approach. Finite range of this potential can be considered as a controllable deformation parameter. The nonclassical quantum statistical properties of this deformed oscillator can be manipulated by nonlinearities associated to the finite range. © 2010 Elsevier B.V.
Physical Review B - Condensed Matter and Materials Physics (10980121)79(16)
In this paper, we investigate phonon effects on the optical properties of a spherical quantum dot. For this purpose, we consider the interaction of a spherical quantum dot with classical and quantum fields while the exciton of quantum dot interacts with a solid-state reservoir. We show that phonons strongly affect the Rabi oscillations and optical coherence on first picoseconds of dynamics. We consider the quantum statistics of emitted photons by quantum dot and we show that these photons are antibunched and obey the sub-Poissonian statistics. In addition, we examine the effects of detuning and interaction of quantum dot with the cavity mode on optical coherence of energy levels. The effects of detuning and interaction of quantum dot with cavity mode on optical coherence of energy levels are compared to the effects of its interaction with classical pulse. © 2009 The American Physical Society.
Journal of Physics B: Atomic, Molecular and Optical Physics (13616455)42(9)
We consider excitons in a quantum dot as q-deformed systems. The interaction of some excitonic systems with one cavity mode is considered. The dynamics of the system is obtained by diagonalizing the total Hamiltonian, and the emission spectrum of a quantum dot is derived. The physical consequences of a q-deformed exciton on the emission spectrum of a quantum dot are given. It is shown that when the exciton system deviates from Bose statistics, the emission spectra will become multi-peak. With our investigation we try to find the origin of the q-deformation of the exciton. The optical response of excitons, which is affected by the nonlinear nature of q-deformed systems, up to the second order of approximation is calculated and the absorption spectrum of the system is given. © 2009 IOP Publishing Ltd.
Journal of Physics A: Mathematical and Theoretical (17518113)42(4)
In this paper we study some basic quantum confinement effects through investigation of a deformed harmonic oscillator algebra. We show that spatial confinement effects on a quantum harmonic oscillator can be represented by a deformation function within the framework of nonlinear coherent states theory. We construct the coherent states associated with the spatially confined quantum harmonic oscillator in a one-dimensional infinite well and examine some of their quantum statistical properties, including sub-Poissonian statistics and quadrature squeezing. © 2009 IOP Publishing Ltd.
Journal of Physics B: Atomic, Molecular and Optical Physics (13616455)41(22)
In this paper, we derive the dynamical algebra of a particle confined in an infinite spherical well using the f-deformed oscillator approach. We consider an exciton with definite angular momentum in a wide quantum dot interacting with two laser beams. We show that under the weak confinement condition, and quantization of the centre-of-mass motion of exciton, its stationary state can be considered as a special kind of nonlinear coherent states which exhibits the quadrature squeezing. © 2008 IOP Publishing Ltd.
