On atomic squeezing in a generalized multiphoton Jaynes–Cummings model

1996 ◽  
Vol 74 (5-6) ◽  
pp. 305-312 ◽  
Author(s):  
Rui-Hua Xie
Keyword(s):  
Dynamical Evolution ◽  
Nonlinear Interactions ◽  
Destructive Effect ◽  
Multiphoton Transition ◽  
Rotating Wave ◽  
Atomic Squeezing

Dynamical evolution of atomic squeezing is studied in a generalized multiphoton Jaynes–Cummings model. The influence of some nonlinear interactions and the counter-rotating wave term on the squeezing is discussed in detail. These nonlinear interactions influence the squeeze duration and its revival period. In a multiphoton transition, switching on the counter-rotating wave term has a much more destructive effect on the squeezing, but this destructive effect is weakened due to the presence of a nonlinear Kerr-like medium.

scholarly journals Study of Squeezing Properties in a Two-level System

1995 ◽  
Vol 48 (6) ◽  
pp. 907 ◽  
Author(s):  
Rui-hua Xie ◽  
Gong-ou Xu ◽  
Dun-huan Liu
Keyword(s):  
Single Mode ◽  
Nonlinear Interactions ◽  
Level System ◽  
Rotating Wave Approximation ◽  
Wave Approximation ◽  
Mode Field ◽  
Level Atom ◽  
Rotating Wave ◽  
Arbitrary Intensity ◽  
Intensity Dependent Coupling

We have studied the squeezing properties of a field and atom in a two-level system. The influence of nonlinear interactions (Le. the arbitrary intensity-dependent coupling of a single-mode field to a single two-level atom, the nonlinear interaction of the field with a nonlinear Kerr-like medium) on the squeezing is discussed in detail in the rotating wave approximation (RWA). We show numerically that the effect of the virtual-photon field suppresses dipole squeezing predicted in the RWA and leads to an increased squeeze revival period; the suppressed squeezing can be revived due to the presence of the nonlinear Kerr-like medium.

Statistical results on discovered near-Earth asteroids

1999 ◽  
Vol 173 ◽  
pp. 81-86
Author(s):  
S. Berinde
Keyword(s):  
Dynamical Evolution ◽  
Minor Planet ◽  
Orbital Elements ◽  
The Earth ◽  
Near Earth Asteroids ◽  
Statistical Results

AbstractThe first part of this paper gives a recent overview (until July 1st, 1998) of the Near-Earth Asteroids (NEAs) database stored at Minor Planet Center. Some statistical interpretations point out strong observational biases in the population of discovered NEAs, due to the preferential discoveries, depending on the objects’ distances and sizes. It is known that many newly discovered NEAs have no accurately determinated orbits because of the lack of observations. Consequently, it is hard to speak about future encounters and collisions with the Earth in terms of mutual distances between bodies. Because the dynamical evolution of asteroids’ orbits is less sensitive to the improvement of their orbital elements, we introduced a new subclass of NEAs named Earth-encounter asteroids in order to describe more reliably the potentially dangerous bodies as impactors with the Earth. So, we pay attention at those asteroids having an encounter between their orbits and that of the Earth within 100 years, trying to classify these encounters.

From the Oort cloud to Halley-type comets

1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo
Keyword(s):  
Total Population ◽  
Complex Function ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Capture Process ◽  
Influx Rate ◽  
Short Period ◽  
Dynamical Properties ◽  
Orbital Periods ◽  
Probability Of Capture

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods < 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.

Exploring Coronal Structures with SOHO

2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard
Keyword(s):  
Solar Corona ◽  
Image Enhancement ◽  
Coronal Mass Ejections ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Low Contrast ◽  
Contrast Structures ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Coronal Structures

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

Evolution of collisional systems

1984 ◽  
Vol 75 ◽  
pp. 361-362
Author(s):  
André Brahic
Keyword(s):  
Gravitational Field ◽  
Dynamical Evolution ◽  
Oblate Planet

AbstractThe dynamical evolution of planetary discs in the gravitational field of an oblate planet and a satellite is numerically simulated.

The Jovian ring

1984 ◽  
Vol 75 ◽  
pp. 203-209
Author(s):  
Joseph A. Burns
Keyword(s):  
Equatorial Plane ◽  
Charged Particles ◽  
Dynamical Evolution ◽  
Main Band ◽  
Small Grains ◽  
Three Components

ABSTRACTLying in Jupiter's equatorial plane is a diaphanous ring having little substructure within its three components (main band, faint disk, and halo). Micron-sized grains account for much of the visible ring, but particles of centimeter sizes and larger must also be present to absorb charged particles. Since dynamical evolution times and survival life times are quite short (≲102-3yr) for small grains, the Jovian ring is being continually replenished; probably most of the visible ring is generated by micrometeoroids colliding into unseen parent bodies that reside in the main band.

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