arXiv subjects

Chanh Q. Kieu

Publications and source records attributed to Chanh Q. Kieu.

3 recordsLinked to original sources

arXiv2006

Coherent Quantum Engineering of Free-Space Laser Cooling

We perform a quantitative analysis of the cooling dynamics of three-level atomic systems interacting with two distinct lasers. Employing sparse-matrix techniques, we find numerical solutions to the fully quantized master equation in steady state. Our method allows straightforward determination of laser-cooling temperatures without the ambiguity often accompanied by semiclassical calculations, and more quickly than non-sparse techniques. Our calculations allow us to develop an understanding of the regimes of cooling, as well as a qualitative picture of the mechanism, related to the phenomenon of electromagnetically induced transparency. Effects of the induced asymmetric Fano-type lineshapes affect the detunings required for optimum cooling, as well as the predicted minimum temperatures which can be lower than the Doppler limit for either transition.

physics.atom-ph↗

arXiv2004

An Analytical Theory for the Early Stage of the Development of Hurricanes: Part I

A theoretical formulation for the early stage (Tropical Storm stage) of hurricane development is proposed. These solutions are not only consistent with observations but also offer some new insights into hurricane properties. This is the first time a theoretical model for the early growing of hurricanes is proposed for which analytical solutions have been found, based on an assumption of a positive feedback of a self-induced developing system.

physics.ao-ph↗

arXiv2004

An Analytical Theory for the Early Stage of the Development of Hurricanes: Part II

In this series of papers, an analytical theory for the early stage (tropical storm stage) of hurricane development is proposed. In Part I, a linear theory and a nonlinear theory have been formulated. It was found in Part I that the linear theory, a kind of the 2D Rankine vortex, gives some unrealistic properties for hurricane development at the upper half of the atmosphere. In the nonlinear theory, the analytical solutions agree well in many dynamical respects with observations at the tropical stage of hurricane development. Particularly, these solutions offer new insights which have not been shown before. However, this nonlinear theory has a disturbing point: a discontinuity of tangential wind and geopotential with radius. In this second Part, this discontinuity will be eliminated satisfactorily without any significant changes to the results obtained in Part I. In addition, the frictional effects will be investigated, which has not been done considered in Part I.

physics.ao-ph↗