scholarly journals Correlated Relation between Quantum Discord and Entanglement of Two-Atom in Thermal Reservoirs

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Xue-Qun Yan ◽  
Zhuan-Lin Yue
Keyword(s):  
Time Evolution ◽  
Strong Correlation ◽  
Quantum Discord ◽  
Photon Number ◽  
Dynamical Evolution ◽  
Evolution Process ◽  
Qubit System ◽  
The Mean ◽  
Evolution Behavior

We study the time evolution of quantum discord and entanglement of a two-qubit system in thermal reservoirs. We find that there are no simple ordering relations between entanglement and quantum discord for the dynamical evolution behavior; that is, quantum discord may be smaller or larger than entanglement in the evolution process. However, a strong correlation between changes of the ordering relations and the mean photon number is found. In addition, it also shows that entanglement is not the strongest form of nonclassicality.

INFLUENCE OF THE COUNTER-ROTATING TERMS ON THE RABI OSCILLATIONS IN THE POLYATOMIC JAYNES-CUMMINGS MODEL WITH CAVITY LOSSES FOR INITIAL FOCK-STATE FIELDS

1996 ◽  
Vol 10 (26) ◽  
pp. 1311-1322
Author(s):  
J. SEKE
Keyword(s):  
Dipole Moment ◽  
Time Evolution ◽  
Population Inversion ◽  
Photon Number ◽  
Numerical Results ◽  
Rabi Oscillations ◽  
Virtual Photons ◽  
Fock State ◽  
The Mean ◽  
Atomic Population Inversion

The significance of the counter-rotating terms in the polyatomic Jaynes-Cummings model with cavity losses is demonstrated. Numerical results for the time evolution of the atomic population inversion and dipole moment for an initial Fock-state field with different photon numbers are presented for various cavity dampings. The appearance of new steady states for the population inversion and the mean-photon number under the influence of the counter-rotating terms is pointed out. Namely, as is shown, the presence of “virtual photons”, produced by the counter-rotating terms, leads to these effects.

INFLUENCE OF THE COUNTER-ROTATING TERMS ON THE RABI OSCILLATIONS AND SQUEEZING IN THE POLYATOMIC JAYNES-CUMMINGS MODEL WITH CAVITY LOSSES FOR INITIAL COHERENT FIELDS

1996 ◽  
Vol 10 (11) ◽  
pp. 487-496
Author(s):  
J. SEKE
Keyword(s):  
Dipole Moment ◽  
Time Evolution ◽  
Population Inversion ◽  
Photon Number ◽  
Steady States ◽  
Numerical Results ◽  
Rabi Oscillations ◽  
Coherent Field ◽  
The Mean ◽  
Atomic Population Inversion

The influence of the counter-rotating terms in the polyatomic Jaynes-Cummings model with cavity losses is investigated. Numerical results for the time evolution of the atomic population inversion, dipole moment, mean-photon number and atomic and field squeezing parameters for an initial coherent field are presented for different cavity dampings. As a consequence of the counter-rotating terms, the appearance of new steady states for the population inversion and the mean-photon number is pointed out.

Quantum discord and entanglement of two atoms in a micromaser-type system

2016 ◽  
Vol 30 (15) ◽  
pp. 1650190
Author(s):  
Xue-Qun Yan ◽  
Fu-Zhong Wang
Keyword(s):  
Time Evolution ◽  
Mixed State ◽  
Quantum Discord ◽  
Type System ◽  
Complete Loss ◽  
Entangled State ◽  
Fock State

The correlations dynamics of two atoms in the case of a micromaser-type system is investigated. We show that the entangled state can be created by initially maximally mixed state and there exist collapse and revival phenomena for the time evolutions of both entanglement and quantum discord under the system considered as the field is initially in the Fock state. Our results confirm that entanglement and quantum discord have similar behaviors in certain time ranges, such as their oscillations during the time evolution being almost in phase, but they also present significant differences, such as quantum discord being maintained even after the complete loss of entanglement. Furthermore, we exhibit clearly that the dynamics of quantum discord under the action of environment are intimately related to the generation and evolution of entanglement.

Assessment of the correlation between the atherogenic index of plasma and cardiometabolic risk factors in children and adolescents: might it be superior to the TG/HDL-C ratio?

2017 ◽  
Vol 30 (9) ◽  
Author(s):  
Nalan Hakime Nogay
Keyword(s):  
Risk Factors ◽  
Children And Adolescents ◽  
Strong Correlation ◽  
Cardiometabolic Risk ◽  
Density Lipoprotein ◽  
Cardiometabolic Risk Factors ◽  
Atherogenic Index ◽  
Fasting Period ◽  
Atherogenic Index Of Plasma ◽  
The Mean

AbstractBackground:Most of the studies investigating the correlation between the atherogenic index of plasma (AIP) and cardiometabolic risk factors have been conducted with adults, while only a limited number of related studies that involved children and adolescents has been conducted. The purpose of this study is to assess the correlation between the AIP and other cardiometabolic risk factors in adolescents.Methods:This study was conducted with 310 girls and 90 boys who were between the ages of 6 and 18 years. After a 10-h fasting period, the biochemical values of the participants were measured in the morning. The anthropometric measurements of the participants were also taken. The AIP was calculated as Log10 (triglycerides/high density lipoprotein-cholesterol; TG/HDL-C).Results:In adolescents between the ages of 12 and 18, the mean AIP of the group with TG ≥130 mg/dL was significantly higher than that of the groups with TG of 90–129 mg/dL and <90 mg/dL. There was a strong correlation between TG and AIP for both boys and girls among the children and adolescents, while there was a strong correlation between the TG/HDL-C ratio and TG only in the boys who were within the 6–11-year-old age group.Conclusions:An increase in AIP is associated with cardiovascular risk factors in children and adolescents other than those seen in adults. Based on the TG/HDL-C ratio, the AIP may be superior as a complementary index in the assessment of cardiometabolic risks in children and adolescents.

The influence of the classical homogenous gravitational field on interaction of a three-level atom with a single mode cavity field

2015 ◽  
Vol 29 (29) ◽  
pp. 1550175 ◽  
Author(s):  
N. H. Abd El-Wahab ◽  
Ahmed Salah
Keyword(s):  
Electromagnetic Field ◽  
Gravitational Field ◽  
Photon Number ◽  
Single Mode ◽  
Temporal Behavior ◽  
Cavity Field ◽  
Text Type ◽  
Level Atom ◽  
The Mean ◽  
Single Mode Cavity

We study the interaction between a single mode electromagnetic field and a three-level [Formula: see text]-type atom in the presence of a classical homogenous gravitational field when the atom is prepared initially in the momentum eigenstate. The model includes the detuning parameters and the classical homogenous gravitational field. The wave function is calculated by using the Schrödinger equation for a coherent electromagnetic field and an atom is in its excited state. The influence of the detuning parameter and the classical homogenous gravitational field on the temporal behavior of the mean photon number, the normalized second-order correlation function and the normal squeezing is analyzed. The results show that the presence of these parameters has an important effect on these phenomena. The conclusion is reached and some features are given.

Effectiveness of Non-Markovian Methods for Quantum Discord Dynamics of Non-coupled Two-Qubit System

2018 ◽  
Vol 70 (3) ◽  
pp. 268 ◽  
Author(s):  
Yong-Gang Huang ◽  
Xiao-Yun Wang ◽  
Xue-Xian Yang ◽  
Ke Deng ◽  
Jin-Zhang Peng ◽  
...  
Keyword(s):  
Quantum Discord ◽  
Qubit System

scholarly journals Quantum Weak Invariants: Dynamical Evolution of Fluctuations and Correlations

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1219
Author(s):  
Zeyi Shi ◽  
Sumiyoshi Abe
Keyword(s):  
Time Evolution ◽  
Open Quantum System ◽  
Dynamical Evolution ◽  
Time Dependent ◽  
Von Neumann Entropy ◽  
Completely Positive Map ◽  
Expectation Values ◽  
Completely Positive ◽  
Temporal Asymmetry ◽  
Von Neumann

Weak invariants are time-dependent observables with conserved expectation values. Their fluctuations, however, do not remain constant in time. On the assumption that time evolution of the state of an open quantum system is given in terms of a completely positive map, the fluctuations monotonically grow even if the map is not unital, in contrast to the fact that monotonic increases of both the von Neumann entropy and Rényi entropy require the map to be unital. In this way, the weak invariants describe temporal asymmetry in a manner different from the entropies. A formula is presented for time evolution of the covariance matrix associated with the weak invariants in cases where the system density matrix obeys the Gorini–Kossakowski–Lindblad–Sudarshan equation.

scholarly journals Poynting-Robertson Effect and Collisions in the Interplanetary Dust Cloud

1980 ◽  
Vol 90 ◽  
pp. 299-302
Author(s):  
Jan Trulsen ◽  
Arild Wikan
Keyword(s):  
Simulation Model ◽  
Dust Cloud ◽  
Dynamical Evolution ◽  
Interplanetary Dust ◽  
Collision Time ◽  
The Mean ◽  
The Individual ◽  
Individual Grains

A simulation model has been developed to study the results of the Poynting-Robertson (PR) effect and collisions on the dynamical evolution of an interplanetary dust cloud. Fragmentational and accretional effects are neglected. With a mean free collision time of the order of the PR lifetime collisional effects become of importance. As the individual grains still spiral inwards collisions act to make the mean eccentricity and inclination of the grain orbits both decrease at comparable rates, giving rise to an expanding fan shaped dust cloud.

scholarly journals Population Synthesis of Old Neutron Stars in the Galaxy

2000 ◽  
Vol 195 ◽  
pp. 181-188
Author(s):  
S. B. Popov ◽  
M. Colpi ◽  
A. Treves ◽  
R. Turolla ◽  
V. M. Lipunov ◽  
...  
Keyword(s):  
Neutron Stars ◽  
Ambient Medium ◽  
Dynamical Evolution ◽  
Low Velocity ◽  
Mean Velocity ◽  
Secular Evolution ◽  
Sky Survey ◽  
The Galaxy ◽  
The Mean ◽  
Statistical Sample

The paucity of old, isolated accreting neutron stars in ROSAT observations is used to derive a lower limit on the mean velocity of neutron stars at birth. The secular evolution of the population is simulated following the paths of a statistical sample of stars for different values of the initial kick velocity, drawn from an isotropic, Gaussian distribution with mean velocity 0 ≤ 〈V〉 ≤ 550 km s−1. The spin-down, induced by dipole losses and the interaction with the ambient medium, is tracked together with the dynamical evolution in the Galactic potential, allowing for the determination of the fraction of stars which are, at present, in each of the four possible stages: Ejector, Propeller, Accretor, and Georotator. Taking from the ROSAT All-Sky Survey an upper limit of ~ 10 accreting neutron stars within ~ 140 pc from the Sun, we infer a lower bound for the mean kick velocity, 〈V〉 ≳ 200–300 km s−1. The same conclusion is reached for both a constant (B ~ 1012 G) and an exponentially decaying magnetic field with a timescale ~ 109 yr. Present results, moreover, constrain the fraction of low-velocity stars which could have escaped pulsar statistics to ≲ 1%.

Determination of Estrogen Receptors in Human Breast Cancer: Comparison between Enzyme Immunoassay and Dextran-Coated Charcoal Method

1986 ◽  
Vol 72 (5) ◽  
pp. 511-514 ◽  
Author(s):  
Cecilia Bozzetti ◽  
Nadia Naldi ◽  
Annamaria Guazzi ◽  
Rita Nizzoli ◽  
Magda Benecchi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Estrogen Receptors ◽  
Enzyme Immunoassay ◽  
Strong Correlation ◽  
Human Breast Cancer ◽  
Human Breast ◽  
Dextran Coated Charcoal ◽  
The Mean

Estrogen receptor determination was performed on 120 breast cancer cytosols, using the dextran-coated charcoal method (DCC) and an enzyme immunoassay (EIA) to compare the efficiency of the two techniques. A strong correlation was noted between ER concentrations determined by DCC and EIA (P < 0.001). The mean ER-EIA value was significantly higher than the mean ER-DCC value in premenopausal (P < 0.001) as well in postmenopausal (P < 0.001) patients.

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