scholarly journals Nonlinear Dynamics of a Cavity Containing a Two-Mode Coherent Field Interacting with Two-Level Atomic Systems

2020 ◽  
Vol 10 (20) ◽  
pp. 7150
Author(s):  
E. M. Khalil ◽  
Hashim M. Alshehri ◽  
A.-B. A. Mohamed ◽  
S. Abdel-Khalek ◽  
A.-S. F. Obada
Keyword(s):  
Quantum Coherence ◽  
Intrinsic Noise ◽  
Noise Model ◽  
Atomic Systems ◽  
Dipole Coupling ◽  
Two Photon ◽  
Dipole Interactions ◽  
Coherent Field ◽  
Noise Rate ◽  
Sudden Appearance

This study analytically explored two coupled two-level atomic systems (TLAS) as two qubits interacting with two modes of an electromagnetic field (EMF) cavity via two-photon transitions in the presence of dipole–dipole interactions between the atoms and intrinsic damping. Using special unitary su(1,1) Lie algebra, the general solution of an intrinsic noise model is obtained when an EMF is initially in a generalized coherent state. We investigated the population inversion of two TLAS and the generated quantum coherence of some partitions (including the EMF, two TLAS, and TLAS–EMF). It is possible to generate quantum coherence (mixedness and entanglement) from the initial pure state. The robustness of the quantum coherence produced and the sudden appearance and disappearance of coherence depended not only on dipole–dipole coupling but also on the intrinsic noise rate. The growth of mixedness and entanglement may be enhanced by increasing dipole–dipole coupling, leading to more robustness against intrinsic noise.

Quantum coherence induced by a flux qubit coupled by a resonator coherent field through a two-photon interaction

2021 ◽  
Author(s):  
Abdel-Baset Mohamed ◽  
Hosny A Hessian ◽  
F. S. Al-Duais ◽  
H Eleuch
Keyword(s):  
Sudden Death ◽  
Coherent States ◽  
Quantum Coherence ◽  
Intrinsic Decoherence ◽  
Photon Interaction ◽  
Two Photon ◽  
Coherent Field ◽  
Flux Qubit

Abstract The intrinsic decoherence effects on a flux qubit coupled to a resonator through a two-photon interaction where the resonator field is initially in coherent and even coherent states are investigated. The qubit-resonator entanglement and coherence loss (mixedness) of the system and its subsystems are examined using entropy and negativity. The ability of the qubit-resonator interaction to generate quantum coherence (qubit-resonator entanglement and the mixedness) is shown to be dependent on the initial cavity non-classicality, detuning, and decoherence. For larger values of the qubit-resonator detuning, the initial resonator non-classicality can enhance the generation and stability of quantum coherence. The decoherence degrades the qubit-resonator entanglement and destroys the sudden death-birth entanglement.

An Exhaustive Analysis of the Characterization of Photopolymer Material (SZ2080) by Two-Photon Polymerization, Waves Moving in a Periodic Potential, and Two-Photon Absorption

2020 ◽  
Vol 1003 ◽  
pp. 165-172 ◽  
Author(s):  
Ritu Walia ◽  
Kamal Nain Chopra
Keyword(s):  
Photonic Crystals ◽  
Quantum Coherence ◽  
Periodic Potential ◽  
Three Dimensional ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Polymerization Waves ◽  
Two Photon Polymerization

This paper presents an Exhaustive Analysis of the Characterization of Photopolymer Material (SZ2080) by Two-Photon Polymerization, and some of the modern concepts like Characterization of Photonic Crystals in Photopolymer SZ2080 by Two-Photon Polymerization, Waves Moving in a Periodic Potential, and Optical Quantum metamaterials. Two-photon polymerization for fabricating three-dimensional subdiffraction-limited structures has been discussed. Experimental and Computed Curves of line thickness (nm) vs feed rate (μm/s) have been technically analyzed. Waves moving in a Periodic Potential and Photonic Crystals have been technically discussed. In addition, Optical Quantum metamaterials have been discussed in terms of quantum coherence, and quantum dots with emphasis on cavity array metamaterial.

The effect of Doppler broadening on dispersive and absorptive properties in atomic systems with two-photon interference

2011 ◽  
Vol 284 (24) ◽  
pp. 5697-5701 ◽  
Author(s):  
Lida Zhang ◽  
Fengxue Zhou ◽  
Yueping Niu ◽  
Jingtao Zhang ◽  
Shangqing Gong
Keyword(s):  
Doppler Broadening ◽  
Atomic Systems ◽  
Two Photon

ATOMIC VELOCITY SELECTION BY INTERFERENCE IN TWO-PHOTON IONIZATION

1996 ◽  
Vol 05 (04) ◽  
pp. 911-919
Author(s):  
J.C. GARREAU ◽  
D. WILKOWSKI ◽  
D. HENNEQUIN ◽  
V. ZEHNLÉ
Keyword(s):  
Electromagnetic Field ◽  
Quantum Interference ◽  
Quantum Coherence ◽  
Degrees Of Freedom ◽  
Internal State ◽  
Center Of Mass ◽  
Mass Motion ◽  
Two Photon ◽  
Selective Ionization ◽  
Velocity Selection

This paper discusses a new scheme for generating quantum coherence between different degrees of freedom of an atom interacting with two modes of the electromagnetic field. The presence of quantum interference in a two-photon coupling between the ground state of the atom and the continuum through two quasi-resonant intermediate states induces selective ionization of the atoms for particular combinations of the different parameters characterizing the degrees of freedom of the system, leading to quantum coherence between the internal state, the center-of-mass motion of the atom, and the electromagnetic field. The application of this method to the selection of an atomic velocity class is discussed.

TWO-LEVEL ATOM UNDERGOING TWO PHOTON TRANSITION IN A QUANTIZED FIELD: THE FLUORESCENT SPECTRUM

1992 ◽  
Vol 06 (12) ◽  
pp. 729-736
Author(s):  
AMITABH JOSHI ◽  
S. V. LAWANDE
Keyword(s):  
Fluorescence Spectrum ◽  
Two Photon ◽  
Photon Transition ◽  
Dressed States ◽  
Level Atom ◽  
Coherent Field ◽  
Fluorescent Spectrum ◽  
Qualitative Nature ◽  
Quantized Field ◽  
The Mean

The fluorescence spectrum produced by a two-photon Jaynes-Cummings model (JCM) has been analyzed using the infinity of transitions among the dressed states of its Hamiltonian. A large number of resonances in the spectra are observed which are sensitive to the mean photon numbers of the quantized coherent field. Also, the qualitative nature of these spectra are in contrast to that of the corresponding spectra of standard JCM.

The two-photon approximation for the four-photon decay of the 4d excited state in hydrogenThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 123-127 ◽  
Author(s):  
D. Solovyev ◽  
L. Labzowsky
Keyword(s):  
Excited State ◽  
Hydrogen Atom ◽  
Early Universe ◽  
Recombination Process ◽  
Atomic Systems ◽  
International Conference ◽  
Two Photon ◽  
Photon Decay ◽  
Hydrogen Recombination ◽  
History Of

The method of two-photon approximation for multiphoton decay is applied to the decay of the 4d state in the hydrogen atom. In the process of four-photon decay the two-photon contribution that leads to radiation escape, from the interaction with matter, is considered. This may be helpful for a strict description of the recombination process in the hydrogen atom and, in principle, for the history of hydrogen recombination in the early universe.

scholarly journals Circuit Models and Experimental Noise Measurements of Micropipette Amplifiers for Extracellular Neural Recordings from Live Animals

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Chang Hao Chen ◽  
Sio Hang Pun ◽  
Peng Un Mak ◽  
Mang I Vai ◽  
Achim Klug ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Intrinsic Noise ◽  
Model Systems ◽  
Noise Model ◽  
Noise Sources ◽  
Extracellular Recordings ◽  
Neural Recordings ◽  
Noise Measurements ◽  
Glass Micropipette

Glass micropipettes are widely used to record neural activity from single neurons or clusters of neurons extracellularly in live animals. However, to date, there has been no comprehensive study of noise in extracellular recordings with glass micropipettes. The purpose of this work was to assess various noise sources that affect extracellular recordings and to create model systems in which novel micropipette neural amplifier designs can be tested. An equivalent circuit of the glass micropipette and the noise model of this circuit, which accurately describe the various noise sources involved in extracellular recordings, have been developed. Measurement schemes using dead brain tissue as well as extracellular recordings from neurons in the inferior colliculus, an auditory brain nucleus of an anesthetized gerbil, were used to characterize noise performance and amplification efficacy of the proposed micropipette neural amplifier. According to our model, the major noise sources which influence the signal to noise ratio are the intrinsic noise of the neural amplifier and the thermal noise from distributed pipette resistance. These two types of noise were calculated and measured and were shown to be the dominating sources of background noise forin vivoexperiments.

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