Wyniki wyszukiwania - BazTech

1

From molecular spectroscopy to entanglement of atoms - a trek with supersonic velocity

Koperski J.

Optica Applicata

|

2012

|

Vol. 42, nr 2

417-431

EN

The supersonic free-jet expansion technique is being used in different fields of research in physics, and physical chemistry to study vibrational and rotational molecular structures in ground and excited electronic energy states. The supersonic beam technique exploits a source of monokinetic, rotationally and vibrationally cold van der Waals (vdW) molecules that are very weakly bound in their ground electronic states. In this article we review experiments at the Jagiellonian University in Kraków (Poland) in which the supersonic free-jet beam serves as a source of ground-state vdW molecules in studies of neutral-neutral interactions between 12-group metal (Me = Zn, Cd, Hg) and 18-group noble gas (Ng = He, Ne, Ar, Kr, Xe) atoms. The experiments lead to determination of spectroscopical characteristics and interatomic potentials of MeNg and Me2 molecules, allowing determination of distinct trends in the Me-Ng and Me-Me interactions in different regions of internuclear separation. The determined interatomic potentials are also used in designing mechanisms of internal vibrational cooling of molecules photoassociated in magneto-optical traps. Recently, versatility of supersonic beams is confirmed in quantum information where the technique is planned to be used to create pairs of entangled atoms in experiments dedicated for testing of Bell's inequality for atoms. A purpose of the experiment - which is in a preparational stage in our laboratory - is to create pairs of entangled cadmium atoms with regard to their nuclear spin orientations. It is planned to be achieved in supersonic molecular beams of cadmium dimers using two dye-laser pulses and stimulated Raman process leading to a controlled photodissociation of the molecule.

2

Entangled cadmium atoms - from the method of production to the test of Bell inequalities

Urbanczyk T., Strojecki M., Krosnicki M., Koperski J.

Optica Applicata

|

2012

|

Vol. 42, nr 2

433-441

EN

We present recent progress in the implementation of experimental realization of a loophole-free test of Bell inequalities for entangled 111Cd atoms. The experimental approach is a modified version of the proposal of Fry and co-workers (Phys. Rev. A 52(6), 1995, p. 4381) for the re-alization of Bohm's 1/2-spin particle version of the Einstein-Podolsky-Rosen (E-P-R) experiment and is based on the production of entangled atoms by photodissociation of the 111Cd2 isotopologue in a supersonic expansion beam using the spectroscopically selective stimulated Raman process.

3

Spectroscopy of Cd2 and Zn2 molecules in free-jet supersonic beams: experimental and theoretical studies

Ruszczak M, Strojecki M, Krośnicki M, Łukomski M, Koperski J

Optica Applicata

|

2006

|

Vol. 36, nr 4

s. 451--459

EN

A method of supersonic beam combined with techniques of laser spectroscopy and simulations of spectra were employed to study interatomic potentials of Cd2 and Zn2 molecules. Total laser induced fluorescence was recorded after an excitation of Cd2 using laser radiation in the range of 2200–2260 Å. The observed structures are interpreted as due to the transitions from υ" = 0 in the ground state to vibrational levels below the potential barrier of the 11u(51P1) electronic state. Studies of Zn2 consisted of simulations of excitation and fluorescence spectra recorded at the transition. In the simulations, both isotopic and rotational structures were taken into account.