ghasem naeimi - Academia.edu (original) (raw)

Papers by ghasem naeimi

Applied Mathematics & Information Sciences

Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for ... more Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for three-level atoms in a weak field approximation method, where probe field is very weaker than the coupling field. The weak field approximation is not valid in full-quantum model where the number of coupling photons is not so large. In the present article, the master equations for the interaction of two-mode photons with a three-level Lambda\LambdaLambda-type atom are exactly solved and the exact dispersion and absorption spectra for the probe beam photons are also obtained analytically. The results of the exact scheme are compared with the corresponding results in the weak field approximation method in full-quantum and semi-classical models.

ISRN Optics, 2013

Measurement of photons number in a quantum cavity is very difficult and the photons number is cha... more Measurement of photons number in a quantum cavity is very difficult and the photons number is changed after each measurement. Recently, many efforts have been done for the nondemolition measurement methods. Haroche et al. succeed in recognizing existence or nonexistence of one photon in a quantum cavity. In this paper, we employ their experimental setup for a quantum nondemolition measurement and pump a coherent state in their quantum cavity. In this case, we could detect more photons in the quantum cavity by a measurement of a displaced Wigner function. It is also shown that the measurement of more than one photon is possible by the Haroche method by measuring just one point of displaced Wigner function. Furthermore, if the cavity field is filled by a superposition of two number states, the average number of photons within the cavity would be measurable. We show that their setup is also suitable to apply for the measurement of the squeezing parameter for the squeezed state of photo...

A comparative study of a qutrit (three-level atomic system) coupled to a classical field in a typ... more A comparative study of a qutrit (three-level atomic system) coupled to a classical field in a typical Markovian reservoir (free space) and in a photonic band-gap (PBG) crystal is carried out. The aim of the study is to assess the collective impact of structured environment and classical control of the system on the dynamics of quantum coherence, non-Markovianity, and estimation of parameters which are initially encoded in the atomic state. We show that the constructive interplay of PBG material as a medium and classical driving field as a part of system results in a significant enhancement of all the quantum traits of interest, compared to the case when the driven qutrit is in a Markovian environment. Our results supply insights for preserving and enhancing quantum features in qutrit systems which are promising alternative candidates to be used in quantum processors instead of qubits.

We propose a method to map the conventional optical interferometry setup into quantum circuits. T... more We propose a method to map the conventional optical interferometry setup into quantum circuits. The unknown phase shift inside a Mach-Zehnder interferometer in the presence of photon loss is estimated by simulating the quantum circuits. For this aim, we use the Bayesian approach in which the likelihood functions are needed, and they are obtained by simulating the appropriate quantum circuits. The precision of four different definite photon-number states of light, which all possess six photons, is compared. In addition, the fisher information for the four definite photon-number states in the setup is also estimated to check the optimality of the chosen measurement scheme.

European Physical Journal Plus, 2020

We propose a novel scheme for asymmetric light diffraction of a weak probe field in a one-dimensi... more We propose a novel scheme for asymmetric light diffraction of a weak probe field in a one-dimensional (1D) and two-dimensional (2D) lattice occupied with cold atoms. The atoms are driven into the double-lambda-type configuration by a standing wave, two coupling laser fields and a probe. Our study suggests the proposed scheme is capable of forming an asymmetric diffraction as a result of inducing optical parity-time symmetry in both 1D and 2D lattices. Moreover, it is demonstrated that the asymmetric pattern of diffraction can be dynamically manipulated by means of adjusting the relative phase. Furthermore, it is revealed that in the case of 1D lattice (grating), intensity variation of the coupling fields has a significant impact on the intensity of diffraction orders.

Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for ... more Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for three-level atoms in a weak field approximation method, where probe field is very wea ker than the coupling field. The weak field approximation is no t valid in full-quantum model where the number of coupling photons is not so large. In the present article, the master equations for the interaction of two-mode photons with a three-level Λ -type atom are exactly solved and the exact dispersion and absorption spectra for the probe beam photons are also obtained analytically. The results of the exact scheme are compared with the corresponding results in the weak field approximation method in full-quantum and semi-classi cal models.

We investigate the dynamics of coherence and entanglement of vibrating qubits. Firstly, we consid... more We investigate the dynamics of coherence and entanglement of vibrating qubits. Firstly, we consider a single trapped ion qubit inside a perfect cavity and successively we use it to construct a bipartite system made of two of such subsystems, taken identical and noninteracting. As a general result, we find that qubit vibration can lead to prolonging initial coherence in both single-qubit and two-qubit system. However, despite of this coherence preservation, we show that the decay of the entanglement between the two qubits is sped up by the vibrational motion of the qubits. Furthermore, we highlight how the dynamics of photon–phonon correlations between cavity mode and vibrational mode, which may serve as a further useful resource stored in the single-qubit system, is strongly affected by the initial state of the qubit. These results provide new insights about the ability of systems made of moving qubits in maintaining quantum resources compared to systems of stationary qubits.

Progress In Electromagnetics Research Letters, 2019

Recently, manipulation and measurement of quantum states, especially in quantum cavities, have at... more Recently, manipulation and measurement of quantum states, especially in quantum cavities, have attracted the attention of many researchers in different fields, such as quantum optics, quantum information, and quantum computation. In this paper, a non-demolition method for the measurement of squeezing parameter via atomic Mach-Zehnder interferometer is presented. An experimental setup was also proposed which included two quantum cavities, in different arms of an atomic Mach-Zehnder interferometer. Each quantum cavity was settled between two classical cavities. Quantum cavities contained entangled states with arbitrary squeezed photons. It is shown that the outgoing atomic states of Mach-Zehnder interferometer carry on the properties and situation of quantum states of the cavities. The squeezing parameter of photonic state for one of the cavities is obtained by the detection of excited and non-excited probabilities of Mach-Zehnder interferometer's outgoing ports, for a train of incoming two-level Rydberg atoms.

Applied Optics

Fraunhofer light diffraction of a weak probe field passing through an asymmetric three-coupled qu... more Fraunhofer light diffraction of a weak probe field passing through an asymmetric three-coupled quantum well, which is driven by a standing wave and two coupling laser fields, is investigated. Depending on which transitions are coupled by the probe and standing field, two schemes are considered. It is demonstrated that owing to the closed-loop transition, optical properties and the diffraction pattern of the probe field in both schemes are highly affected by the relative phase of the applied fields and can be controlled by this parameter. Moreover, it is shown that the proposed schemes have multifunction capabilities. In the first scheme, as a result of varying relative phase, the electromagnetically induced absorption phase grating turns to the electromagnetically induced gain phase grating with remarkable efficiency, while in the latter scheme, a significant result is revealed: Tuning the relative phase can lead to inducing optical parity-time symmetry, which gives rise to an asymmetric diffraction grating. Such an all-optical phase-sensitive operation could be useful in optical switching and optical communications.

SpringerPlus

Background Electromagnetically induced transparency (EIT) has been theoretically introduced by Ko... more Background Electromagnetically induced transparency (EIT) has been theoretically introduced by Kocharovskaya and Khanin (1988) and experimentally observed, by Harris et al. (1990) and Harris (1997). Recently, many authors have been interested in studying EIT and its applications (

Applied Mathematics and Physics, 2014

Generation and manipulation of multi-qubits or multi-partite entangled states are cornerstones of... more Generation and manipulation of multi-qubits or multi-partite entangled states are cornerstones of manufacturing quantum computers and developing quantum information. In this paper, we develop a new scheme for the generation of a multi-partite maximally entangled state generation. This method has less limitation and is simpler than the previous ones. It is based on the interactions of a chain of Rydberg Rubidium atoms with an array of five high quality cavities, including four classical and one quantum cavity in the middle.

Applied Mathematics & Information Sciences

Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for ... more Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for three-level atoms in a weak field approximation method, where probe field is very weaker than the coupling field. The weak field approximation is not valid in full-quantum model where the number of coupling photons is not so large. In the present article, the master equations for the interaction of two-mode photons with a three-level Lambda\LambdaLambda-type atom are exactly solved and the exact dispersion and absorption spectra for the probe beam photons are also obtained analytically. The results of the exact scheme are compared with the corresponding results in the weak field approximation method in full-quantum and semi-classical models.

ISRN Optics, 2013

Measurement of photons number in a quantum cavity is very difficult and the photons number is cha... more Measurement of photons number in a quantum cavity is very difficult and the photons number is changed after each measurement. Recently, many efforts have been done for the nondemolition measurement methods. Haroche et al. succeed in recognizing existence or nonexistence of one photon in a quantum cavity. In this paper, we employ their experimental setup for a quantum nondemolition measurement and pump a coherent state in their quantum cavity. In this case, we could detect more photons in the quantum cavity by a measurement of a displaced Wigner function. It is also shown that the measurement of more than one photon is possible by the Haroche method by measuring just one point of displaced Wigner function. Furthermore, if the cavity field is filled by a superposition of two number states, the average number of photons within the cavity would be measurable. We show that their setup is also suitable to apply for the measurement of the squeezing parameter for the squeezed state of photo...

A comparative study of a qutrit (three-level atomic system) coupled to a classical field in a typ... more A comparative study of a qutrit (three-level atomic system) coupled to a classical field in a typical Markovian reservoir (free space) and in a photonic band-gap (PBG) crystal is carried out. The aim of the study is to assess the collective impact of structured environment and classical control of the system on the dynamics of quantum coherence, non-Markovianity, and estimation of parameters which are initially encoded in the atomic state. We show that the constructive interplay of PBG material as a medium and classical driving field as a part of system results in a significant enhancement of all the quantum traits of interest, compared to the case when the driven qutrit is in a Markovian environment. Our results supply insights for preserving and enhancing quantum features in qutrit systems which are promising alternative candidates to be used in quantum processors instead of qubits.

We propose a method to map the conventional optical interferometry setup into quantum circuits. T... more We propose a method to map the conventional optical interferometry setup into quantum circuits. The unknown phase shift inside a Mach-Zehnder interferometer in the presence of photon loss is estimated by simulating the quantum circuits. For this aim, we use the Bayesian approach in which the likelihood functions are needed, and they are obtained by simulating the appropriate quantum circuits. The precision of four different definite photon-number states of light, which all possess six photons, is compared. In addition, the fisher information for the four definite photon-number states in the setup is also estimated to check the optimality of the chosen measurement scheme.

European Physical Journal Plus, 2020

We propose a novel scheme for asymmetric light diffraction of a weak probe field in a one-dimensi... more We propose a novel scheme for asymmetric light diffraction of a weak probe field in a one-dimensional (1D) and two-dimensional (2D) lattice occupied with cold atoms. The atoms are driven into the double-lambda-type configuration by a standing wave, two coupling laser fields and a probe. Our study suggests the proposed scheme is capable of forming an asymmetric diffraction as a result of inducing optical parity-time symmetry in both 1D and 2D lattices. Moreover, it is demonstrated that the asymmetric pattern of diffraction can be dynamically manipulated by means of adjusting the relative phase. Furthermore, it is revealed that in the case of 1D lattice (grating), intensity variation of the coupling fields has a significant impact on the intensity of diffraction orders.

Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for ... more Semi-quantum or full-quantum electromagnetically induced transparency has been fully studied for three-level atoms in a weak field approximation method, where probe field is very wea ker than the coupling field. The weak field approximation is no t valid in full-quantum model where the number of coupling photons is not so large. In the present article, the master equations for the interaction of two-mode photons with a three-level Λ -type atom are exactly solved and the exact dispersion and absorption spectra for the probe beam photons are also obtained analytically. The results of the exact scheme are compared with the corresponding results in the weak field approximation method in full-quantum and semi-classi cal models.

We investigate the dynamics of coherence and entanglement of vibrating qubits. Firstly, we consid... more We investigate the dynamics of coherence and entanglement of vibrating qubits. Firstly, we consider a single trapped ion qubit inside a perfect cavity and successively we use it to construct a bipartite system made of two of such subsystems, taken identical and noninteracting. As a general result, we find that qubit vibration can lead to prolonging initial coherence in both single-qubit and two-qubit system. However, despite of this coherence preservation, we show that the decay of the entanglement between the two qubits is sped up by the vibrational motion of the qubits. Furthermore, we highlight how the dynamics of photon–phonon correlations between cavity mode and vibrational mode, which may serve as a further useful resource stored in the single-qubit system, is strongly affected by the initial state of the qubit. These results provide new insights about the ability of systems made of moving qubits in maintaining quantum resources compared to systems of stationary qubits.

Progress In Electromagnetics Research Letters, 2019

Recently, manipulation and measurement of quantum states, especially in quantum cavities, have at... more Recently, manipulation and measurement of quantum states, especially in quantum cavities, have attracted the attention of many researchers in different fields, such as quantum optics, quantum information, and quantum computation. In this paper, a non-demolition method for the measurement of squeezing parameter via atomic Mach-Zehnder interferometer is presented. An experimental setup was also proposed which included two quantum cavities, in different arms of an atomic Mach-Zehnder interferometer. Each quantum cavity was settled between two classical cavities. Quantum cavities contained entangled states with arbitrary squeezed photons. It is shown that the outgoing atomic states of Mach-Zehnder interferometer carry on the properties and situation of quantum states of the cavities. The squeezing parameter of photonic state for one of the cavities is obtained by the detection of excited and non-excited probabilities of Mach-Zehnder interferometer's outgoing ports, for a train of incoming two-level Rydberg atoms.

Applied Optics

Fraunhofer light diffraction of a weak probe field passing through an asymmetric three-coupled qu... more Fraunhofer light diffraction of a weak probe field passing through an asymmetric three-coupled quantum well, which is driven by a standing wave and two coupling laser fields, is investigated. Depending on which transitions are coupled by the probe and standing field, two schemes are considered. It is demonstrated that owing to the closed-loop transition, optical properties and the diffraction pattern of the probe field in both schemes are highly affected by the relative phase of the applied fields and can be controlled by this parameter. Moreover, it is shown that the proposed schemes have multifunction capabilities. In the first scheme, as a result of varying relative phase, the electromagnetically induced absorption phase grating turns to the electromagnetically induced gain phase grating with remarkable efficiency, while in the latter scheme, a significant result is revealed: Tuning the relative phase can lead to inducing optical parity-time symmetry, which gives rise to an asymmetric diffraction grating. Such an all-optical phase-sensitive operation could be useful in optical switching and optical communications.

SpringerPlus

Background Electromagnetically induced transparency (EIT) has been theoretically introduced by Ko... more Background Electromagnetically induced transparency (EIT) has been theoretically introduced by Kocharovskaya and Khanin (1988) and experimentally observed, by Harris et al. (1990) and Harris (1997). Recently, many authors have been interested in studying EIT and its applications (

Applied Mathematics and Physics, 2014

Generation and manipulation of multi-qubits or multi-partite entangled states are cornerstones of... more Generation and manipulation of multi-qubits or multi-partite entangled states are cornerstones of manufacturing quantum computers and developing quantum information. In this paper, we develop a new scheme for the generation of a multi-partite maximally entangled state generation. This method has less limitation and is simpler than the previous ones. It is based on the interactions of a chain of Rydberg Rubidium atoms with an array of five high quality cavities, including four classical and one quantum cavity in the middle.