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Interaction-induced decay of a heteronuclear two-atom system.

Xu P, Yang J, Liu M, He X, Zeng Y, Wang K, Wang J, Papoular DJ, Shlyapnikov GV, Zhan M - Nat Commun (2015)

Bottom Line: One of the key quantities is the inelastic relaxation (decay) time when one of the atoms or both are in a higher hyperfine state.This experimental method allows us to single out a particular relaxation process thus provides an extremely clean platform for collisional physics studies.Our results have also implications for engineering of quantum states via controlled collisions and creation of two-qubit quantum gates.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, and Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China [2] Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China.

ABSTRACT
Two-atom systems in small traps are of fundamental interest for understanding the role of interactions in degenerate cold gases and for the creation of quantum gates in quantum information processing with single-atom traps. One of the key quantities is the inelastic relaxation (decay) time when one of the atoms or both are in a higher hyperfine state. Here we measure this quantity in a heteronuclear system of (87)Rb and (85)Rb in a micro optical trap and demonstrate experimentally and theoretically the presence of both fast and slow relaxation processes, depending on the choice of the initial hyperfine states. This experimental method allows us to single out a particular relaxation process thus provides an extremely clean platform for collisional physics studies. Our results have also implications for engineering of quantum states via controlled collisions and creation of two-qubit quantum gates.

No MeSH data available.


Related in: MedlinePlus

Experimental setup and measurement time sequence.(a) Schematic diagram of the experimental setup. Two 830-nm lasers are collimated, combined by a polarizing beam splitter (PBS) and then strongly focused by an objective (Linos, HALO30) into the vacuum chamber to form two ODTs. The movable ODT is from 830-nm laser-1 and can be shifted to overlap with the static ODT (from 830-nm laser-2) by controlling piezoelectric ceramic transducer (PZT)-1. The fluorescence of trapped single atoms is collected by the same objective, separated from dipole lasers by a dichroic mirror (DM) and guided to single-photon-counting module (SPCM) for detection. PZT-2 controls the fluorescence-collecting region. A detailed description can be found in Methods. (b) Time sequence in the experiment. Each survival probability in our experiment is the result from 300 repeated measurements.
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f1: Experimental setup and measurement time sequence.(a) Schematic diagram of the experimental setup. Two 830-nm lasers are collimated, combined by a polarizing beam splitter (PBS) and then strongly focused by an objective (Linos, HALO30) into the vacuum chamber to form two ODTs. The movable ODT is from 830-nm laser-1 and can be shifted to overlap with the static ODT (from 830-nm laser-2) by controlling piezoelectric ceramic transducer (PZT)-1. The fluorescence of trapped single atoms is collected by the same objective, separated from dipole lasers by a dichroic mirror (DM) and guided to single-photon-counting module (SPCM) for detection. PZT-2 controls the fluorescence-collecting region. A detailed description can be found in Methods. (b) Time sequence in the experiment. Each survival probability in our experiment is the result from 300 repeated measurements.

Mentions: Our two-atom heteronuclear system is composed of a single 85Rb and a single 87Rb in a micro optical dipole trap (ODT), and there are three important points in the experiment. The first one is a sequential trapping of a single 87Rb in a static ODT and a single 85Rb in a movable ODT23, and we make sure that two atoms of different isotopes are actually trapped (see Fig. 1 and Methods). Second, we shift the movable ODT to overlap with the static one, and adiabatically turn off the movable trap. We get 87Rb and 85Rb in one trap with probability of about 95%. The third point is that the collisional blockade24 does not allow us to detect the presence of 87Rb or 85Rb when both of them are in the same trap. Therefore, we first have to kick out one of the atoms to detect the presence of the other one. By optimizing this procedure we have minimized unwanted atom losses to <3%.


Interaction-induced decay of a heteronuclear two-atom system.

Xu P, Yang J, Liu M, He X, Zeng Y, Wang K, Wang J, Papoular DJ, Shlyapnikov GV, Zhan M - Nat Commun (2015)

Experimental setup and measurement time sequence.(a) Schematic diagram of the experimental setup. Two 830-nm lasers are collimated, combined by a polarizing beam splitter (PBS) and then strongly focused by an objective (Linos, HALO30) into the vacuum chamber to form two ODTs. The movable ODT is from 830-nm laser-1 and can be shifted to overlap with the static ODT (from 830-nm laser-2) by controlling piezoelectric ceramic transducer (PZT)-1. The fluorescence of trapped single atoms is collected by the same objective, separated from dipole lasers by a dichroic mirror (DM) and guided to single-photon-counting module (SPCM) for detection. PZT-2 controls the fluorescence-collecting region. A detailed description can be found in Methods. (b) Time sequence in the experiment. Each survival probability in our experiment is the result from 300 repeated measurements.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525158&req=5

f1: Experimental setup and measurement time sequence.(a) Schematic diagram of the experimental setup. Two 830-nm lasers are collimated, combined by a polarizing beam splitter (PBS) and then strongly focused by an objective (Linos, HALO30) into the vacuum chamber to form two ODTs. The movable ODT is from 830-nm laser-1 and can be shifted to overlap with the static ODT (from 830-nm laser-2) by controlling piezoelectric ceramic transducer (PZT)-1. The fluorescence of trapped single atoms is collected by the same objective, separated from dipole lasers by a dichroic mirror (DM) and guided to single-photon-counting module (SPCM) for detection. PZT-2 controls the fluorescence-collecting region. A detailed description can be found in Methods. (b) Time sequence in the experiment. Each survival probability in our experiment is the result from 300 repeated measurements.
Mentions: Our two-atom heteronuclear system is composed of a single 85Rb and a single 87Rb in a micro optical dipole trap (ODT), and there are three important points in the experiment. The first one is a sequential trapping of a single 87Rb in a static ODT and a single 85Rb in a movable ODT23, and we make sure that two atoms of different isotopes are actually trapped (see Fig. 1 and Methods). Second, we shift the movable ODT to overlap with the static one, and adiabatically turn off the movable trap. We get 87Rb and 85Rb in one trap with probability of about 95%. The third point is that the collisional blockade24 does not allow us to detect the presence of 87Rb or 85Rb when both of them are in the same trap. Therefore, we first have to kick out one of the atoms to detect the presence of the other one. By optimizing this procedure we have minimized unwanted atom losses to <3%.

Bottom Line: One of the key quantities is the inelastic relaxation (decay) time when one of the atoms or both are in a higher hyperfine state.This experimental method allows us to single out a particular relaxation process thus provides an extremely clean platform for collisional physics studies.Our results have also implications for engineering of quantum states via controlled collisions and creation of two-qubit quantum gates.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, and Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China [2] Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China.

ABSTRACT
Two-atom systems in small traps are of fundamental interest for understanding the role of interactions in degenerate cold gases and for the creation of quantum gates in quantum information processing with single-atom traps. One of the key quantities is the inelastic relaxation (decay) time when one of the atoms or both are in a higher hyperfine state. Here we measure this quantity in a heteronuclear system of (87)Rb and (85)Rb in a micro optical trap and demonstrate experimentally and theoretically the presence of both fast and slow relaxation processes, depending on the choice of the initial hyperfine states. This experimental method allows us to single out a particular relaxation process thus provides an extremely clean platform for collisional physics studies. Our results have also implications for engineering of quantum states via controlled collisions and creation of two-qubit quantum gates.

No MeSH data available.


Related in: MedlinePlus