Cooling of atoms

One of the most exciting areas in atomic physics in the last 10 years has been laser cooling of translational motion in atoms to 10 3-10-9 K [9, 10, 15]. Several variations on cooling of atomic translational motion have now been proposed, but the generic scheme is as follows Two monochromatic laser beams are propagated, one along and one opposite an atomic beam by tuning the frequency of the laser to the red of resonance with a sharp... 

DOPPLER COOLING The first ideas for laser cooling of atoms [6] and ions [7] were published in 1975. The basic idea of what is now called Doppler cooling can be understood by referring to the famous picture. Here we see a typical atomic resonance curve, which we can take to show the rate at which an atom... 

CONCLUSIONS Optical lattices have allowed a series of new measurements on the trapping and cooling of atoms in laser fields. We have measured the rates of cooling and observed... 

Although the recoil effect is very small when a single photon is absorbed, it can be used effectively for optical cooling of atoms by the cumulative effect of many absorbed photons. This can be seen as follows When atom A stays for the time T in a laser field that is in resonance with the transition j) ), the atom may absorb and emit a photon tko many times, provided the optical pumping cycle is short compared to T and the atom behaves like a true two-level system. This means that the emission of fluorescence photons fuo by the excited atom in level k) brings the atom back only to the initial state i), but never to other levels. With the saturation parameter S = Bikp (Oik)/Aik, the fraction of excited atoms becomes... 

Fig. 9.8 Laser cooling of atoms in a collimated beam with a fixed laser frequency and Zeeman tuning of the atomic absorption frequency [1125]...

A very interesting alternative laser for optical cooling of atoms in a collimated beam is the modeless laser [1131], which has a broad spectral emission (without mode stmcture, when averaged over a time of T > 10 ns, with an adjustable bandwidth and a tunable center frequency). Such a laser can cool all atoms regardless of their velocity if its spectral width Ao>l is larger than the Doppler shift Acod = vok [1132]. 

A schematic diagram of an apparatus for optical cooling of atoms, deflection of the slowed-down atoms, and focusing is depicted in Fig. 9.13. 

Three-dimensional Cooling of Atoms Optical Molasses... 

C. Salomon, Laser cooling of atoms and ion trapping for frequency standards, in Metrology at the Frontiers of Physics and Technology, ed. by L. Crovini, T.J. Quinn (Noith-HoUand, Amsterdam, 1992), p. 405... 

The increasing research on laser cooling of atoms and molecules and many experiments with Bose-Einstein condensates have brought about some remarkable results... 

Although the recoil effect is very small when a single photon is absorbed, it can be used effectively for optical cooling of atoms by the cumulative effect of many absorbed photons. This can be seen as follows ... 

The increasing research on laser cooling of atoms and molecules and many experiments with Bose-Einstein condensates have brought about some remarkable results and have considerably increased our knowledge about the interaction of light with matter on a microscopic scale and the interatomic interactions at very low temperatures. Also the realization of coherent matter waves (atom lasers) and investigations of interference effects between matter waves have proved fundamental aspects of quantum mechanics. 

Parkins AS and Zoller P. Laser cooling of atoms with broadband real Gaussian laser fields. Physical Review A 1992 May l 45(9) 6522-6538. 

H. Metcalf, W.D. Phillips Laser cooling of atomic beams Comments. At. Mol. Phys. 16, 79 (1985). 

S. Chu, L. Hollberg, J.E. Bjorkholm, A. Cable, A. Ashkin Three-dimensional viscous confinement and cooling of atoms by resonance radiation pressure. Phys. Rev. Lett. 55, 48 (1985)... 

For performing precision measurements of their properties, ultracold atoms and molecules are one of the central themes of current fundamental research in chemical and optical physics. Laser cooling of atoms allows micro-Kelvin... 

The cooling of atoms to ultracold temperatures has resulted in spectacular discoveries. The realization and study of new states of matter like Bose Einstein Condensates/ degenerate Fermi gases and (Bardeen,... 

Discuss techniques to achieve laser cooling of atoms. 

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