Coherent quantum engineering of free-space laser cooling

Abstract

Secondary circulations (SC) associated with hurricanes are traditionally regarded as small perturbations superimposed on the primary circulations (PC). The reason behind this treatment roots in an observation that the magnitude of the SC is about 10 orders of magnitude smaller than that of the PC. This serves a wide range of hurricane theories up until now with some considerable successes. Recently, Kieu (2004) proposes a revitalizing theory for the development of hurricanes in which the author is able to obtain a class of exact solutions of the primitive equations which shares some of the most important dynamical aspects with observations. According to this theory, the SC turns out to be particular important in determining the three-dimensional structure and time evolution of axisymmetric hurricanes. Kieu's theory, however, contains an infinite growth of the SC that all hurricane theories so far encounter in attempt to modeling the development of hurricanes. In this study, it will be shown that the infinite growth does not occur. In fact, the solution becomes stationary after a period of time and the SC is able to maintain itself without blowing exponentially with time if the nonlinear terms in the vertical momentum equation are included. In addition, the SC tends to force the peripheral convection to converge toward the center, and thus builds up a more concentric vortex with a typical hurricane eye structure. Some potential roles of SC in the formation of hurricane eyes are also discussed.

Measurement of the spin-forbidden decay rate(3s3d)1D2→(3s3Therkildsen1, Jensen2, Ryder3 et al. 2009Phys. Rev. ASelf Cite4130View full textAdd to dashboardCite

“…In a series of papers two photon cooling in ladder schemes have been proposed to lower the temperature below the doppler limit of alkaline earth elements [4,5,6]. The magnesium and calcium systems are of particular interest since cooling is limited to a few mK.…”

Temperature limits in laser cooling of free atoms with three-level cascade transitions

“…This is not necessarily the point of maximum slope in the curve of the absorption coefficient [19]. By looking indirectly at this curve in Fig.…”

“…The Hamiltonian operator H in the bare-states basis and using the rotating wave approximation is given by [19] …”

“…This required quenching the transition by coupling it to an upper level with faster decay rate [16,17]. A last scheme involved the opposite situation, in which the lower transition is broad, or strongly allowed * Corresponding author: flavio@ifi.unicamp.br (such as cooling transitions in alkaline atoms), and the upper is narrower or weaker [18][19][20]. Cooling is obtained when they are simultaneously excited by two lasers in an electromagnetically induced transparency (EIT) fashion, e.g., by a weak ("probe") and a strong ("dressing") laser which, respectively, drive the strong and the weak transitions.…”

“…An extension of the technique was also proposed for cooling of antihydrogen [24]. Despite experimental and theoretical work [18][19][20][21][22][23], the question of what is the Doppler limit for laser cooling with three-level cascade transitions still needs to be clarified. Previous analysis [18,20] stated that minimum temperatures would approach the limit given by the narrower of the two transitions.…”