Atom optics

A beam of slow atoms can be manipulated in many ways. This is performed within the field of atom optics [9.445-9.447]. An atomic beam can be bent or focused using laser fields. An atomic beam can also be reflected at an optical surface using the evanescent optical field from a laser beam reflected from the other side of the surface. The atom version of the Yoimg double-slit experiment has been performed, even with monochromatic thermal atoms, showing clearly the existence of matter waves [9.448]. Beam splitters for slow atomic beams can be optically achieved to build atomic interferometers based on de Broglie wave interference. The thermal de Broglie wavelength 

Cooled atoms enable fundamental experiments in collision physics [9.452]. When the particles move very slowly, scattering can be described accurately by theory. The study of collisions is also important since they constitute a loss mechanism in laser cooling. On the other hand, collisions are necessary to achieve the evaporative cooling needed for Bose-Einstein condensation (see below). 

Cooling has also been achieved for molecules without laser techniques, but employing interaction with cold helium gas or by using a pulsed electric field [9.453]. Clearly, many fundamental studies can be performed on well-prepared samples of cooled molecules. 

Laser cooling and trapping, and atomic optics constitute important aspects of the mechanical effects of light on atoms. Several other such effects exist and have been explored. Studied phenomena include light diffusive pulling [9.454], light-induced drift and the optical piston [9.455]. 

The methods developed for manipulating atomic motion with laser light, briefly described in Chapters 5 and 6, have led naturally to the creation of atom optics. 

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Ohtsu, M. (ed.) (1998) Near-Field Nano/ Atom Optics and Technology, Springer, Tokyo. 

The stability of scarred states to external noise and other environmental disturbances was the next natural issue that was raised and partially addressed earlier (L. Sirko, et.al., 1993 R. Scharf, et.al., 1994). The main conclusion was that scarred states are quite robust to reasonable levels of noise. This question took on added relevance with the coming of age of mesoscopic systems where, be it spontaneous emission in atom optics or leads or scattering and other forms of dissipation in heterostructures, the open nature of the system must be accounted for. These new experiments also provided non-ideal realizations of simple theoretical paradigms such as stadium billiards and the kicked rotor, with additional issues that had to be accounted for in the theory. 

Problem 5.25 (a) What is the necessary and sufficient condition for the existence of enantiomers (6) What is the necessary and sufficient condition for measurement of optical activity (c) Are all substances with chiral atoms optically active and resolvable (d) Are enantiomers possible in molecules that do not have chiral carbon atoms (e) Can a prochiral carbon ever be primary or tertiary (/) Can conformational enantiomers ever be resolved ... 

Figure 1.5 Schematics of basic components of analytical techniques based on atomic optical spectrometry, (a) Atomic absorption spectrometry (b) atomic fluorescence spectrometry (c) atomic emission spectrometry.

Centre for Atom Optics and Ultrafast Spectroscopy, School of Biophysical Sciences and Electrical Engineering, Swinburne University of Technology, Melbourne, Australia 3122... 

V. I. Balykin and V. S. Letokhov, Atom Optics with Laser Light, Harwood, Harwood Acad. Publ. (Chur, 1995). 

Subsequent insertions lead to chain growth. Chain termination takes place by /3-hydrogen transfer to the transition metal atom or to a complex-bound olefin, resulting in formation of the hydride or alkyl transition metal compound in addition to the oligomer. The former allows new insertion steps to occur. The dimers formed do not contain a chiral carbon atom. Optical activity is observed first in trimers and higher oligomers (203,204). 

Asymmetry of the Cobalt Atom.—Optically active compounds of cobalt have been produced, indicating that their structure is asymmetric.1... 

Arc/Spark Atomic (Optical) Emission Spectrometry summary ... 

The second, time-reversed, process uses scattering of electrons by atoms optically pumped by a laser, i.e. 

A(q) = e q) + q2/(2m ) — q.V being the energy mismatch between the the states in) and q). The second term in the square brackets in Eq. (7b) arises from the coupling-constant renormalization in Eq. (4) and compensates for the ultraviolet divergence of the first term. This compensation is completely analogous to that of the electron mass renormalization in calculations of the radiative shift of an atomic optical transition [Bethe 1947 Cohen-Tannoudji 1992],... 

The very first demonstration of molecule interference dates back to the days of Estermann and Stern [Estermann 1930] who demonstrated experimentally diffraction of 11-2 at a LiF crystal surface in 1930. Further experiments with diatomic molecules had to await progress and interest in atom optics. A Ramsey-Borde interferometer was realized for the iodine dimer in 1994 [Borde 1994] and was recently used [Lisdat 2000] with K. Similarly, a Mach-Zehnder interferometer was demonstrated [Chapman 1995 (a)] for Na2. The nearfield analog to the Mach-Zehnder interferometer, a Talbot-Lau interferometer, was recently applied to experiments with L12 [Berman 1997], Diffraction at nanofabricated gratings also turned out to be the most effective way to prove the existence of weakly bound helium dimer [Schollkopf 1996] and to measure its binding energy [Grisenti 2000],... 

ATOM OPTICS WITH BOSE-EINSTEIN CONDENSATION USING OPTICAL POTENTIALS... 

Abstract Using our Bose-Einstein condensation (BEC) machine and the Bragg spectroscopy technique we study excitation evolution and decay in BEC. New results have been achieved with this system, and are reported here. We also develop various theoretical models for simulating atomic optical behavior in dynamically changing trapping schemes. 

Keywords Atom optics, Bose-Einstein condensation, optical potentials... 

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