Laser spectroscopy of Ba+ ions in superfluid He and in cold He gas
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Asia/Tokyo
203 (RIBF bldg.)
203
RIBF bldg.
Description
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The 19th Nuclear Spectroscopy Laboratory Seminar
第19回 核分光研セミナー
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Lecturer: Peter Moroshkin (RIKEN, Center for Emergent Matter science)
Title: Laser spectroscopy of Ba+ ions in superfluid He and in cold He gas
Language: English
Date: Jul. 27 (Wed.), 2016, 13:30-
Place: RIBF bldg. #203
Abstract: Free electrons and He+ ions trapped at the surface of liquid He represent a model two-dimensional electronic system that is widely used in experiments. Much less is known about the properties of foreign atomic ions interacting with the liquid He surface. In contrast to free electrons and He+ ions, the ions of various metallic elements can be observed and manipulated by methods of laser spectroscopy that offers exciting new perspectives for the entire field of 2D electronic systems at liquid He surfaces [1].
In my talk, I will discuss the properties of impurity ions in superfluid He and in cold He gas, with a special emphasis on Ba+ ions that are used in our experiments [2]. Ba+ is a model hydrogen-like system with a single valence electron outside the closed electronic shells. The interaction between the ion and surrounding He atoms strongly depends on the shape of the valence electron density distribution. For the spherically symmetric 6 2S1/2 and 6 2P1/2 states, it can be described in the frame of the atomic bubble model. On the other hand, the strongly anisotropic 6 2P3/2, 5 2D3/2, and 5 2D5/2 states lead to the formation of excimer and exciplex quasimolecules. The structures of both types can be identified in our experiments via their laser-induced fluorescence spectra. These experiments have been carried out in bulk superfluid He and in a cryogenic Ba-He plasma. I will also present our ongoing efforts aiming at the trapping of Ba+ ions under the free surface of superfluid He.
[1] R. Batulin et al., J. Low Temp. Phys. 175, 63 (2014)
[2] P. Moroshkin, K. Kono, Phys. Rev. A 93, 052510 (2016)
Host laboratory: Nuclear spectroscopy laboratory
Contact person: Aiko Takamine icot@riken.jp
