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Title: Crystallization of Ca{sup +} ions in a linear rf octupole ion trap

Abstract

A laser-cooling experiment with Ca{sup +} ions trapped in a linear rf octupole ion trap is presented. The phase transition of the laser-cooled Ca{sup +} ions from the cloud to the crystal state is observed by an abrupt dip of the laser-induced fluorescence spectrum and indicates that mK temperatures are obtained. We have also performed molecular dynamics simulations under various conditions to confirm this property by deducing axially symmetric structures of Coulomb crystals and by evaluating the translational temperatures of the laser-cooled ions. The simulation results show that for small numbers of ions novel ring-shaped crystals are produced. As the number of ions is increased, cylindrical layers in the ring crystal are sequentially formed. For more than 100 ions, also hexagonal and spiral structures emerge in parts of the large-size ion crystal, which has a length on the order of millimeters for the present geometrical arrangement and voltages. An advantage of the linear rf octupole trap is its large almost-field-free region in the middle of the trap, where the micromotion amplitude is small for trapped ions. These results demonstrate that such a multipole trap has attractive features for quantum computing and ultracold ion-atom collision studies.

Authors:
; ; ; ; ;  [1];  [2];  [3];  [4]
  1. Department of Physics, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554 (Japan)
  2. (Japan)
  3. (United States)
  4. (ILS), University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585 (Japan)
Publication Date:
OSTI Identifier:
20982357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.75.033409; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; AXIAL SYMMETRY; CALCIUM IONS; CRYSTALLIZATION; CYLINDRICAL CONFIGURATION; ELECTRIC POTENTIAL; FLUORESCENCE; FLUORESCENCE SPECTROSCOPY; ION-ATOM COLLISIONS; IONIC CRYSTALS; LASER RADIATION; MOLECULAR DYNAMICS METHOD; MOLECULAR STRUCTURE; OCTUPOLES; PHASE TRANSFORMATIONS; PHOTON-ATOM COLLISIONS; QUANTUM COMPUTERS; TEMPERATURE RANGE 0000-0013 K; TRAPPING; TRAPS

Citation Formats

Okada, Kunihiro, Yasuda, Kazuhiro, Takayanagi, Toshinobu, Wada, Michiharu, Schuessler, Hans A., Ohtani, Shunsuke, Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Department of Physics, Texas A and M University, College Station, Texas 77843, and Institute for Laser Science. Crystallization of Ca{sup +} ions in a linear rf octupole ion trap. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.033409.
Okada, Kunihiro, Yasuda, Kazuhiro, Takayanagi, Toshinobu, Wada, Michiharu, Schuessler, Hans A., Ohtani, Shunsuke, Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Department of Physics, Texas A and M University, College Station, Texas 77843, & Institute for Laser Science. Crystallization of Ca{sup +} ions in a linear rf octupole ion trap. United States. doi:10.1103/PHYSREVA.75.033409.
Okada, Kunihiro, Yasuda, Kazuhiro, Takayanagi, Toshinobu, Wada, Michiharu, Schuessler, Hans A., Ohtani, Shunsuke, Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Department of Physics, Texas A and M University, College Station, Texas 77843, and Institute for Laser Science. Thu . "Crystallization of Ca{sup +} ions in a linear rf octupole ion trap". United States. doi:10.1103/PHYSREVA.75.033409.
@article{osti_20982357,
title = {Crystallization of Ca{sup +} ions in a linear rf octupole ion trap},
author = {Okada, Kunihiro and Yasuda, Kazuhiro and Takayanagi, Toshinobu and Wada, Michiharu and Schuessler, Hans A. and Ohtani, Shunsuke and Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 and Department of Physics, Texas A and M University, College Station, Texas 77843 and Institute for Laser Science},
abstractNote = {A laser-cooling experiment with Ca{sup +} ions trapped in a linear rf octupole ion trap is presented. The phase transition of the laser-cooled Ca{sup +} ions from the cloud to the crystal state is observed by an abrupt dip of the laser-induced fluorescence spectrum and indicates that mK temperatures are obtained. We have also performed molecular dynamics simulations under various conditions to confirm this property by deducing axially symmetric structures of Coulomb crystals and by evaluating the translational temperatures of the laser-cooled ions. The simulation results show that for small numbers of ions novel ring-shaped crystals are produced. As the number of ions is increased, cylindrical layers in the ring crystal are sequentially formed. For more than 100 ions, also hexagonal and spiral structures emerge in parts of the large-size ion crystal, which has a length on the order of millimeters for the present geometrical arrangement and voltages. An advantage of the linear rf octupole trap is its large almost-field-free region in the middle of the trap, where the micromotion amplitude is small for trapped ions. These results demonstrate that such a multipole trap has attractive features for quantum computing and ultracold ion-atom collision studies.},
doi = {10.1103/PHYSREVA.75.033409},
journal = {Physical Review. A},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}