scholarly journals Tavis–Cummings Model with Moving Atoms

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 452
Author(s):  
Sayed Abdel-Khalek ◽  
Kamal Berrada ◽  
Eied M. Khalil ◽  
Hichem Eleuch ◽  
Abdel-Shafy F. Obada ◽  
...  
Keyword(s):  
Power Law ◽  
Coupling Parameter ◽  
Dynamical Behavior ◽  
Single Mode ◽  
Von Neumann Entropy ◽  
Von Neumann ◽  
Mode Field ◽  
Nonlinear Version ◽  
Power Law Exponent ◽  
Potential Applications

In this work, we examine a nonlinear version of the Tavis–Cummings model for two two-level atoms interacting with a single-mode field within a cavity in the context of power-law potentials. We consider the effect of the particle position that depends on the velocity and acceleration, and the coupling parameter is supposed to be time-dependent. We examine the effect of velocity and acceleration on the dynamical behavior of some quantumness measures, namely as von Neumann entropy, concurrence and Mandel parameter. We have found that the entanglement of subsystem states and the photon statistics are largely dependent on the choice of the qubit motion and power-law exponent. The obtained results present potential applications for quantum information and optics with optimal conditions.

scholarly journals Quantumness Measures for a System of Two Qubits Interacting with a Field in the Presence of the Time-Dependent Interaction and Kerr Medium

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 635
Author(s):  
Sayed Abdel-Khalek ◽  
Kamal Berrada ◽  
Eied M. Khalil ◽  
Abdel-Shafy F. Obada ◽  
Esraa Reda ◽  
...  
Keyword(s):  
Single Mode ◽  
Dynamical Behaviour ◽  
Time Dependent ◽  
Von Neumann Entropy ◽  
Kerr Medium ◽  
Von Neumann ◽  
Mode Field ◽  
Mandel’S Parameter ◽  
Qubit System ◽  
Dependent Interaction

In this work, we introduce the standard Tavis-Cummings model to describe two-qubit system interacting with a single-mode field associated to power-law (PL) potentials. We explore the effect of the time-dependent interaction and the Kerr-like medium. We solve the Schrödinger equation to obtain the density operator that allows us to investigate the dynamical behaviour of some quantumness measures, such as von Neumann entropy, negativity and Mandel’s parameter. We provide how these entanglement measures depend on the system parameters, which paves the way towards better control of entanglement generation in two-qubit systems. We find that the enhancement and preservation of the atoms-field entanglement and atom-atom entanglement can be achieved by a proper choice of the initial parameters of the field in the absence and presence of the time-dependent interaction and Kerr medium. We examine the photons distribution of the field and determine the situations for which the field exhibits super-poissonian, poissonian or sub-poissonian distribution.

scholarly journals Statistical Study of the Entanglement for Qubit Interacting with an Electromagnetic Field

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Neveen Sayed-Ahmed ◽  
M. M. Amein ◽  
Taghreed M. Jawa ◽  
Tahani A. Aloafi ◽  
F. S. Bayones ◽  
...  
Keyword(s):  
Binomial Distribution ◽  
Numerical Study ◽  
Single Mode ◽  
Simulation Method ◽  
Von Neumann Entropy ◽  
Quantum Model ◽  
Wigner Functions ◽  
Von Neumann ◽  
Proposed Model ◽  
Distribution State

A statistical method is applied to predict the behaviour of a quantum model consisting of a qubit interacting with a single-mode cavity field. The qubit is prepared in excited state while the field starts from the binomial distribution state. The wave function of the proposed model is obtained. A von Neumann entropy is used to investigate the behaviour of the entanglement between the field and the qubits. Moreover, the atomic Q and Wigner functions are used to identify the behaviour of the distribution in a phase space. The simulation method is used to estimate the parameters of the proposed model to reach the best results. A numerical study is performed to estimate the specific dependency of the binomial distribution state. The results of entanglement were compared with the atomic Q and Wigner functions. The results showed that there are many maximum values of entanglement periodically. The results also confirmed a correlation between von Neumann entropy, the atomic Q , and Wigner functions.

On the interaction between a time-dependent field and a two-level atom

2019 ◽  
Vol 34 (10) ◽  
pp. 1950081 ◽  
Author(s):  
N. H. Abdel-Wahab ◽  
Ahmed Salah
Keyword(s):  
Quantum Electrodynamics ◽  
Initial Conditions ◽  
Coupling Parameter ◽  
Quantum Systems ◽  
Trapped Ions ◽  
Time Dependent ◽  
Von Neumann Entropy ◽  
Von Neumann ◽  
Level Atom ◽  
Dependent Field

In this paper, we study the interaction between the time-dependent field and a two-level atom with one mode electromagnetic field. We consider that the field of photons is assumed to be coupled with modulated coupling parameter which depends explicitly on time. It is shown that the considered model can be reduced to a well-known form of the time-dependent generalized Jaynes–Cummings model. Under special initial conditions, in which the atom and the field are prepared in the excited and the coherent states, respectively, the explicit time evolution of the wave function of the entire system is analytically obtained. Our proposal has many advantages over the previous optical schemes and can be realized in several multiple experiments, such as trapped ions and quantum electrodynamics cavity. The influence of the time-dependent field parameter on the collapses-revivals, the normal squeezing of the radiation, the anti-bunching of photons and the entanglement phenomena for the considered atomic system is examined. The linear entropy, the von Neumann entropy are used to quantify entanglement in the quantum systems. We noticed that these phenomena are affected by the existence of both the time-dependent coupling field and detuning parameters.

Quantum Entanglement and Geometric Phase of Two Moving Two-Level Atoms

2015 ◽  
Vol 22 (03) ◽  
pp. 1550015 ◽  
Author(s):  
S. Abdel-Khalek
Keyword(s):  
Geometric Phase ◽  
Essential Role ◽  
Coupling Parameter ◽  
Atomic Motion ◽  
Von Neumann Entropy ◽  
Field Mode ◽  
Von Neumann ◽  
Nonlocal Correlations ◽  
Interesting Correlation ◽  
Important Kind

An important kind of interaction between two moving two-level atoms and a field mode, where the coupling parameter is taken to be time-dependent, is presented in this paper. Nonlocal correlations between the atoms and the field have been investigated by means of concurrence and von Neumann entropy in terms of the involved parameters of the system. The results show that the atomic motion plays an essential role in the evolution of system dynamics, its nonlocal correlations and geometric phase. Moreover, an interesting correlation between the entanglement and the geometric phase during the evolution was observed. The presented system can be very useful for generating and maintaining high amount of entanglement by means of controlling the parameters of atomic motion.

scholarly journals Spectral Structure and Many-Body Dynamics of Ultracold Bosons in a Double-Well

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 382
Author(s):  
Frank Schäfer ◽  
Miguel A. Bastarrachea-Magnani ◽  
Axel U. J. Lode ◽  
Laurent de Forges de Parny ◽  
Andreas Buchleitner
Keyword(s):  
Initial Conditions ◽  
Dynamical Behavior ◽  
Particle Interaction ◽  
Interaction Strength ◽  
Von Neumann Entropy ◽  
Spectral Structure ◽  
Many Body ◽  
Point Energy ◽  
Von Neumann ◽  
Body Dynamics

We examine the spectral structure and many-body dynamics of two and three repulsively interacting bosons trapped in a one-dimensional double-well, for variable barrier height, inter-particle interaction strength, and initial conditions. By exact diagonalization of the many-particle Hamiltonian, we specifically explore the dynamical behavior of the particles launched either at the single-particle ground state or saddle-point energy, in a time-independent potential. We complement these results by a characterization of the cross-over from diabatic to quasi-adiabatic evolution under finite-time switching of the potential barrier, via the associated time evolution of a single particle’s von Neumann entropy. This is achieved with the help of the multiconfigurational time-dependent Hartree method for indistinguishable particles (MCTDH-X)—which also allows us to extrapolate our results for increasing particle numbers.

scholarly journals The Jaynes–Cummings model of a two-level atom in a single-mode para-Bose cavity field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Fakhri ◽  
M. Sayyah-Fard
Keyword(s):  
Coherent States ◽  
Quantum Noise ◽  
Single Mode ◽  
Von Neumann Entropy ◽  
Cavity Field ◽  
Squeezing Effect ◽  
Atomic Inversion ◽  
Von Neumann ◽  
Level Atom ◽  
Mechanical Nature

AbstractThe coherent states in the parity deformed analog of standard boson Glauber coherent states are generated, which admit a resolution of unity with a positive measure. The quantum-mechanical nature of the light field of these para-Bose states is studied, and it is found that para-Bose order plays an important role in the nonclassical behaviors including photon antibunching, sub-Poissonian statistics, signal-to-quantum noise ratio, quadrature squeezing effect, and multi-peaked number distribution. Furthermore, we consider the Jaynes-Cummings model of a two-level atom in a para-Bose cavity field with the initial states of the excited and Glauber coherent ones when the atom makes one-photon transitions, and obtain exact energy spectrum and eigenstates of the deformed model. Nonclassical properties of the time-evolved para-Bose atom-field states are exhibited through evaluating the fidelity, evolution of atomic inversion, level damping, and von Neumann entropy. It is shown that the evolution time and the para-Bose order control these properties.

scholarly journals Dispersive reservoir influence on the superconducting phase qubit

2015 ◽  
Vol 13 (07) ◽  
pp. 1550056 ◽  
Author(s):  
H. A. Hessian ◽  
A.-B. A. Mohamed ◽  
A. H. Homid
Keyword(s):  
Dynamical Behavior ◽  
Analytical Description ◽  
Negative Eigenvalue ◽  
Von Neumann Entropy ◽  
Initial State ◽  
Von Neumann ◽  
Damping Parameter ◽  
Reservoir Parameter ◽  
Resonator System ◽  
Phase Qubit

An analytical description of a superconducting (SC) phase qubit coupled to a torsional resonator, which is damped by a dispersive reservoir, is presented based on the master equation. Therefore, the effect of the qubit phase damping on the dynamical behavior of the entanglement, purity loss and qubit inversion are investigated. It is found that the collapse and revival phenomena of qubit inversion are very sensitive not only to the damping parameter but also to the frequency detuning and the qubit distribution angle of the initial state. It is interesting to note that the purity of the state of the SC-qubit, which is measured by von Neumann entropy, can be completely lost due to the dispersive reservoir parameter. Because of the existence of dispersive reservoir, the von Neumann entropy cannot be a measure for the entanglement in open system. So, the negative eigenvalue of the partially transposed density matrix of qubit-resonator system is used to quantify the entanglement. For certain parameter sets, it is possible to control the degree and the dynamics of entanglement between the qubit and the torsional resonator.

Mode field diameter measurement conditions in single-mode fibres

1989 ◽  
Vol 25 (8) ◽  
pp. 493
Author(s):  
M. Ohashi ◽  
N. Shibata ◽  
K. Sato
Keyword(s):  
Single Mode ◽  
Diameter Measurement ◽  
Mode Field ◽  
Mode Field Diameter
Sign in / Sign up

Export Citation Format

Share Document