scholarly journals Collapse and revival of entanglement between qubits coupled to a spin coherent state

2018 ◽  
Vol 16 (02) ◽  
pp. 1850017 ◽  
Author(s):  
Iskandar Bahari ◽  
Timothy P. Spiller ◽  
Shane Dooley ◽  
Anthony Hayes ◽  
Francis McCrossan
Keyword(s):  
Coherent State ◽  
Ion Trap ◽  
Coupled System ◽  
Single Mode ◽  
Dipole Interaction ◽  
Circuit Qed ◽  
Field Mode ◽  
Molecular Systems ◽  
Spin Coherent State ◽  
Set Up

We extend the study of the Jayne–Cummings (JC) model involving a pair of identical two-level atoms (or qubits) interacting with a single mode quantized field. We investigate the effects of replacing the radiation field mode with a composite spin, comprising [Formula: see text] qubits, or spin-1/2 particles. This model is relevant for physical implementations in superconducting circuit QED, ion trap and molecular systems. For the case of the composite spin prepared in a spin coherent state, we demonstrate the similarities of this set-up to the qubits-field model in terms of the time evolution, attractor states and in particular the collapse and revival of the entanglement between the two qubits. We extend our analysis by taking into account an effect due to qubit imperfections. We consider a difference (or “mismatch”) in the dipole interaction strengths of the two qubits, for both the field mode and composite spin cases. To address decoherence due to this mismatch, we then average over this coupling strength difference with distributions of varying width. We demonstrate in both the field mode and the composite spin scenarios that increasing the width of the “error” distribution increases suppression of the coherent dynamics of the coupled system, including the collapse and revival of the entanglement between the qubits.

Transient spectrum of sin2-pulsed driven harmonic oscillator

2014 ◽  
Vol 23 (04) ◽  
pp. 1450052
Author(s):  
S. S. Hassan ◽  
R. A. Alharbey ◽  
H. Al-Zaki
Keyword(s):  
Coherent State ◽  
Harmonic Oscillator ◽  
Pulse Shape ◽  
Coupled System ◽  
Single Mode ◽  
Central Peak ◽  
Hole Burning ◽  
Initial Amplitude ◽  
Fluorescent Spectrum ◽  
Initial Excitation

Exact analytical results are derived for the coupled system of nondissipative single mode quantized harmonic oscillator (HO) and arbitrary pulse shape. Specifically, for a sin2-pulse shape, the transient fluorescent spectrum is obtained in the general case of initial coherent state |α〉 of the HO. The dominant central Lorentzian is surrounded by weak oscillations due to the larger number of sequential pulses which get amplified asymmetrically in the nonresonant case as a result of balancing and interference processes between the initial excitation (|α2|) and the strength of the exciting pulse. Further pronounced oscillations is noticed with "hole burning" structure in the central peak due to nonzero phase of the initial amplitude (α).

scholarly journals Entanglement and geometric phase of the coherent field interacting with a three two-level atoms in the presence of non-linear terms

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 237-245
Author(s):  
Eman Hilal ◽  
Sadah Alkhateeb ◽  
Sayed Abel-Khalek ◽  
Eied Khalil ◽  
Amjaad Almowalled
Keyword(s):  
Coherent State ◽  
Geometric Phase ◽  
Initial Conditions ◽  
Von Neumann Entropy ◽  
Field Mode ◽  
Von Neumann ◽  
Coherent Field ◽  
Non Linear ◽  
Atomic States ◽  
The Impact

We study the interaction of a three two-level atoms with a one-mode optical coherent field in coherent state in the presence of non-linear Kerr medim. The three atoms are initially prepared in upper and entangled states while the field mode is in a coherent state. The constants of motion, three two-level atoms and field density matrix are obtained. The analytic results are employed to perform some investigations of the temporal evolution of the von Neumann entropy as measure of the degree of entanglement between the three two-level atoms and optical coherent field. The effect of the detuning and the initial atomic states on the evolution of geometric phase and entanglement is analyzed. Also, we demonstrate the link between the geometric phase and non-classical properties during the evolution time. Additionally the effect of detuning and initial conditions on the Mandel parameter is studied. The obtained results are emphasize the impact of the detuning and the initial atomic states of the feature of the entanglement, geometric phase and photon statistics of the optical coherent field.

scholarly journals Coupling effects in single-mode and multimode resonator-coupled system

2019 ◽  
Vol 27 (13) ◽  
pp. 17718 ◽  
Author(s):  
Cuixiu Xiong ◽  
Hongjian Li ◽  
Hui Xu ◽  
Mingzhuo Zhao ◽  
Baihui Zhang ◽  
...  
Keyword(s):  
Coupled System ◽  
Single Mode ◽  
Coupling Effects

A FOUR-LEVEL ATOM INTERACTING WITH A SINGLE-MODE CAVITY FIELD: DOUBLE Ξ-CONFIGURATION

2008 ◽  
Vol 22 (26) ◽  
pp. 2587-2599 ◽  
Author(s):  
N. H. ABDEL-WAHAB
Keyword(s):  
Coherent State ◽  
Time Evolution ◽  
Single Mode ◽  
Cavity Field ◽  
Field System ◽  
Input Field ◽  
Level Atom ◽  
Constants Of Motion ◽  
Q Function ◽  
Single Mode Cavity

In this article, the problem of a double Ξ-type four-level atom interacting with a single-mode cavity field is considered. The considered model describes several distinct configurations of a four-level atom. Also, this model includes the detuning parameters of the atom-field system. We obtain the constants of motion and the wavefunction is derived when the atom is initially prepared in the upper state. We used this model for computing a number of the field aspects for the considered system. As an illustration, the model is used for studying the time evolution of the Mandel Q-parameter, amplitude-squared squeezing phenomenon and Q-function when the input field is considered in a coherent state. The results show that these phenomena are affected by the presence of detuning parameters.

scholarly journals Photoionization study of Kr+and Xe+ions with the combined use of a merged-beam set-up and an ion trap

2011 ◽  
Vol 44 (5) ◽  
pp. 055205 ◽  
Author(s):  
J M Bizau ◽  
C Blancard ◽  
M Coreno ◽  
D Cubaynes ◽  
C Dehon ◽  
...  
Keyword(s):  
Ion Trap ◽  
Combined Use ◽  
Set Up

scholarly journals On-chip photonic transistor based on the spike synchronization in circuit QED

2018 ◽  
Vol 32 (08) ◽  
pp. 1850088 ◽  
Author(s):  
Yusuf Gül
Keyword(s):  
Single Photon ◽  
Impedance Matching ◽  
Normal Modes ◽  
Single Mode ◽  
Circuit Qed ◽  
Gain Enhancement ◽  
Input Field ◽  
Cavity System ◽  
Photon Conversion ◽  
On Chip

We consider the single photon transistor in coupled cavity system of resonators interacting with multilevel superconducting artificial atom simultaneously. Effective single mode transformation is used for the diagonalization of the Hamiltonian and impedance matching in terms of the normal modes. Storage and transmission of the incident field are described by the interactions between the cavities controlling the atomic transitions of lowest lying states. Rabi splitting of vacuum-induced multiphoton transitions is considered in input/output relations by the quadrature operators in the absence of the input field. Second-order coherence functions are employed to investigate the photon blockade and delocalization–localization transitions of cavity fields. Spontaneous virtual photon conversion into real photons is investigated in localized and oscillating regimes. Reflection and transmission of cavity output fields are investigated in the presence of the multilevel transitions. Accumulation and firing of the reflected and transmitted fields are used to investigate the synchronization of the bunching spike train of transmitted field and population imbalance of cavity fields. In the presence of single photon gate field, gain enhancement is explained for transmitted regime.

MINIMUM UNCERTAINTY RELATION OBEYED BY SWH PHASE OPERATOR IN TWO-MODE COHERENT STATE

1999 ◽  
Vol 13 (14) ◽  
pp. 463-469 ◽  
Author(s):  
FAN HONGYI ◽  
SUN ZHIHU
Keyword(s):  
Coherent State ◽  
Uncertainty Relation ◽  
Phase Measurement ◽  
Single Mode ◽  
Square Root ◽  
Phase Operator ◽  
Expectation Values ◽  
Measurement Scheme ◽  
Minimum Uncertainty ◽  
Root Operation

We study the minimum uncertainty relation obeyed by the phase operator [Formula: see text] in two-mode coherent state. The operator is suitable for Shapiro–Wagner heterodyne phase measurement scheme. It is due to the |ξ> representation (see Eq. (4)) that the difficulty brought by nonlinear square root operation in [Formula: see text] can be avoided in calculating miscellaneous expectation values. Just as the single-mode coherent state | z1> makes uncertainty relation, satisfied by S–G phase operator, minimum for large |z1|2, we show that |z1,z2> makes uncertainty relation obeyed by [Formula: see text] minimum when |z1|=|z2| is large enough. Some figures are plotted to support our conclusion.

Sub-Poissonian photon statistics of light in interaction of two-level atoms in superposed states with a single mode superposed coherent radiation

2010 ◽  
Vol 88 (3) ◽  
pp. 181-188 ◽  
Author(s):  
Rakesh Kumar ◽  
Hari Prakash
Keyword(s):  
Coherent State ◽  
Single Mode ◽  
Fano Factor ◽  
Coherent Radiation ◽  
Photon Statistics ◽  
Coupling Constant ◽  
Large Coupling ◽  
Definite Relationship ◽  
Level Atom ◽  
Coupling Time

We study sub-Poissonian photon statistics of light in interaction of a single mode radiation, initially either in a coherent state or in a superposed coherent state with an assembly of two-level atoms using the Hamiltonian, H = ω(a+a + Sz) + g(aS+ + a+ S–) in natural units, where a+ and a are creation and annihilation operators, Sz, S ± are the collective Dicke operators, g is the coupling constant, and ω is the energy of the photons and also the separation between the two atomic levels. We study the cases of (i) a single two-level and (ii) of two two-level atoms interacting with a single mode coherent or superposed coherent radiation. We find that for large coupling time gt, Fano factor shows collapses and revival phenomena, and that the variation is large for small mean number of photons. We also find that in the case of two two-level atoms, photon statistics shows larger sub-Poissonian than the case of a single two-level atom, and that there is no definite relationship between squeezing and sub-Poissonian photon statistics of light.

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