Kinematic trapping

Figure 1 is a plot of kinematic viscosity, at 25°C, for varying molar ratios of methanol to bis(2-ethylhexyl) sodium sulfosuccinate. Three distinct regions are observed, and each is denoted by dotted vertical lines and designated as either bound methanol, trapped methanol, or apparently free methanol. Eicke... 

For an organic crystalline monolayer it was found that the exciton-exciton kinematic interaction can be described as scattering, not by hard spheres as in 3D crystals, but as scattering by hard disks. It was shown also that, as in the case of a two-dimensional ultracold trapped atom boson gas, the excitons in a confined monolayer may behave as a dilute degenerate boson gas at low temperature. Then for a microcavity with an organic crystalline monolayer such as a resonant material the polariton-polariton kinematic interaction steming from the polariton excitonic part was derived. 

There are two key side effects of the velocity dependent force. First, kinematic cooling results in real cooling, not just a rotation of position-momentum phase space, yielding an increased phase space for the cold molecules. Second, since there is dissipation, if the collisions occur in a region containing a trap for the molecules, the trap can be continuously loaded without the worry of how to load pre-cooled molecules into a conservative potential well. 

Fig. 8.16. Schematic of a magneto-optical trap (MOT) used for kinematic cooling of molecules. A MOT is formed from 6 counter propagating lasers and a set of anti-Helmhotz coils. The MOT keeps an atomic sample near ImK while molecules impinge on the trapped atoms, some fraction of the molecules are kinematically cooled.

The kinematic cooling technique we propose is to collide hot molecules with cold atoms in a magneto-optical trap. Since no specific impact angle is required, the molecules can impact the MOT from any angle, thus the molecules can either impinge on the MOT in the form of a molecular beam or as background gas. This technique is illustrated in Fig. 8.16. 

Kinematic cooling of molecules via collisions with Magneto-Optically trapped atoms provides a straightforward, yet undemonstrated, method for producing cold molecules in environments where they can undergo thermal-izing collisions with cold atoms and potentially be further sympathetically cooled into the ultracold regime. 

We will first describe spectroscopy on collimated atomic beams and on kinematically compressed ion beams. Two groups of nonlinear spectroscopic tecliniques will be discussed saturation techniques and two-photon absorption techniques. We will also deal with the optical analogy to the Ramsey fringe technique (Sect. 7.1.2). In a subsequent section (Sect. 9.8) laser cooling and atom- and ion-trap techniques will be discussed. Here, the particles are basically brought to rest, ehminating the Doppler as well as the transit broadening effects. 

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