Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0908.2929 · Physical Review A

Repeating collisions in an optical trap and the evaluation of spin-dependent interactions among neutral particles

Zhibing Li, Zihao Chen, Yuan Zhang He, Bao Cheng-guang

Published Sep 16, 2010• 2 citations
arXivHTMLPDF

Abstract

A dynamic process of repeating collisions of a pair of trapped neutral particles with weak spin-dependent interaction is designed and studied. A related theoretical derivation and numerical calculation have been performed to study the inherent coordinate-spin and momentum-spin correlations. Because of the repeating collisions, the effect of the weak interaction can be accumulated and enlarged, and therefore can be eventually detected. Numerical results suggest that the Cr-Cr interaction, which has not yet been completely clarified, could thereby be determined. The design can be used in general to determine various interactions among neutral atoms and molecules, in particular for the determination of very weak forces.

DOI
10.1103/physreva.82.032708

Related papers

Repeating 3-body collisions in a trap and the evaluation of interactions of neutral particles

Bao Cheng-guang

A model of a device is proposed and related theoretical calculation is performed to study the weak interactions among neutral atoms and molecules. In this model 3-body collisions among the neutral particles occur repeatedly in a trap. Results of calculation demonstrate that information on interaction can be obtained by observing the time-dependent densities of the system.

arXiv:1001.2352•Jan 14, 2010•0 citations

Trapped scattering with three incident channels and the evaluation of the three-body forces

Bao Cheng-guang

A design of trapped scattering is proposed and related theoretical calculation is performed to evaluate the weak three-body interactions among neutral atoms and molecules. Different from traditional experiments of scattering, the design has three incident channels; three-body collisions would occur in a trap repeatedly, and the number of collisions can be controlled. Hence, the effect of each collision can be accumulated and eventually enlarged. Therefore the design is particularly suitable for the cases with very weak interactions. Results of the calculation demonstrate that, once the two-body force of a species has been known, information on the three-body force can be thereby obtained.

Physical Review A•Nov 10, 2010•0 citations

Two-body scattering in a trap and a special periodic phenomenon sensitive to the interaction

Y. Z. He, Bao Cheng-guang

Two-body scattering of neutral particles in a trap is studied theoretically. The control of the initial state is realized by using optical traps. The collisions inside the trap occur repeatedly; thereby the effect of interaction can be accumulated. Two periodic phenomena with a shorter and a much longer period, respectively, are found. The latter is sensitive to the interaction. Instead of measuring the differential cross section as is usually done, the measurement of the longer period and the details of the periodic behavior might be a valid source of information on weak interactions among neutral particles.

arXiv:1001.1467•Physical Review A•May 17, 2010•2 citations

Atomic collisions in an optical trap

Carl Wieman, David W. Sesko, Thad G Walker +1 more

Spontaneous force light traps1,2 have provided a way to obtain relatively deep static traps for neutral atoms. However, the usefulness of any such trap will depend strongly on the density of the trapped atoms. We have studied the collisions within such a trap which limit the atomic density. These collisions are of considerable interest in their own right because the temperatures of the trapped atoms (10−4 K) are far lower than in usual atomic collision experiments. As a result the collision times are very long, and the collision dynamics are dominated by long-range interactions and spontaneous emission.

Quantum Electronics and Laser Science Conference•Apr 24, 1989•0 citations

Constructing correlated spin states with neutral atoms in optical lattices

Artur Widera

This thesis reports on the experimental investigation of controlled spin dependent interactions in a sample of ultracold Rubidium atoms trapped in a periodic optical potential. In such a situation, the most basic interaction between only two atoms at one common potential well, forming a micro laboratory for this atom pair, can be investigated. Spin dependent interactions between the atoms can lead to an intriguing time evolution of the system. In this work, we present two examples of such spin interaction induced dynamics. First, we have been able to observe and control a coherent spin changing interaction. Second, we have \nachieved to examine and manipulate an interaction\ninduced time evolution of the relative phase of a spin 1/2-system, both in the case of particle pairs and in the more general case of N interacting particles. The first part of this thesis elucidates the spin-changing interaction mechanism underlying many fascinating effects resulting from interacting spins at ultracold temperatures. This process changes the spin states of two colliding particles, while preserving total magnetization. If initial and final states have almost equal energy, this process is resonant and leads to large amplitude\noscillations between different spin states. The measured coupling parameters of such a process allow to precisely infer atomic scattering length differences, that e.g. determine the nature of the magnetic ground state of the hyperfine states in Rubidium.\nMoreover, a method to tune the spin oscillations at will based on the AC-Zeeman effect has been implemented. This allowed us to use resonant spin changing \ncollisions as a quantitative and non-destructive particle pair probe in the optical lattice. This led to a series of experiments shedding light on the Bosonic superfluid to Mott insulator transition.\nIn a second series of experiments we have been able to coherently manipulate the interaction induced time evolution of the relative phase in an ensemble of spin 1/2-systems. For two particles, interactions can lead to an entanglement oscillation of the particle pair. For the general case of N interacting particles, the ideal time evolution leads to the creation of spin squeezed states and even Schrödinger cat states. In the experiment we have been able to control the underlying\ninteractions by a Feshbach resonance. For particle pairs we could directly observe the entanglement oscillations. For the many particle case we have been able to observe and reverse the interaction induced dispersion of the relative phase.\nThe presented results demonstrate how correlated spin states can be engineered through \ncontrol of atomic interactions. Moreover, the results point towards the possibility to simulate quantum\nmagnetism phenomena with ultracold atoms in optical traps, and to realize and analyze many novel quantum spin states which have not been experimentally realized so far.

•Jan 1, 2007•4 citations

Two-Fermion Scattering on Momentum-Representation in a Trap and Their Periodic Phenomena

Yi-Zhong Fang, Y. Z. He

Under the control of the prepared initial state, two-body scattering of trapped neutral fermions is studied theoretically. Since the fermions collide inside the trap frequently, the effect of atom-atom interaction can be accumulated. On the momentum-representation, we find the presence of periodic probability density, which is much longer than that of bosons. The measurement and details of this periodic phenomenon might be valid information about weak interactions among neutral particles.

Chinese Physics Letters•Aug 1, 2011•0 citations
A dynamic process of repeating collisions of a pair of trapped neutral particles with weak spin-dependent interaction is designed and studied. A related theoretical derivation and numerical calculation have been performed to study the inherent coordinate-spin and momentum-spin correlations. Because of the repeating collisions, the effect of the weak interaction can be accumulated and enlarged, and therefore can be eventually detected. Numerical results suggest that the Cr-Cr interaction, which has not yet been completely clarified, could thereby be determined. The design can be used in general to determine various interactions among neutral atoms and molecules, in particular for the determination of very weak forces.
A design of trapped scattering is proposed and related theoretical calculation is performed to evaluate the weak three-body interactions among neutral atoms and molecules. Different from traditional experiments of scattering, the design has three incident channels; three-body collisions would occur in a trap repeatedly, and the number of collisions can be controlled. Hence, the effect of each collision can be accumulated and eventually enlarged. Therefore the design is particularly suitable for the cases with very weak interactions. Results of the calculation demonstrate that, once the two-body force of a species has been known, information on the three-body force can be thereby obtained.
Two-body scattering of neutral particles in a trap is studied theoretically. The control of the initial state is realized by using optical traps. The collisions inside the trap occur repeatedly; thereby the effect of interaction can be accumulated. Two periodic phenomena with a shorter and a much longer period, respectively, are found. The latter is sensitive to the interaction. Instead of measuring the differential cross section as is usually done, the measurement of the longer period and the details of the periodic behavior might be a valid source of information on weak interactions among neutral particles.
Spontaneous force light traps1,2 have provided a way to obtain relatively deep static traps for neutral atoms. However, the usefulness of any such trap will depend strongly on the density of the trapped atoms. We have studied the collisions within such a trap which limit the atomic density. These collisions are of considerable interest in their own right because the temperatures of the trapped atoms (10−4 K) are far lower than in usual atomic collision experiments. As a result the collision times are very long, and the collision dynamics are dominated by long-range interactions and spontaneous emission.
This thesis reports on the experimental investigation of controlled spin dependent interactions in a sample of ultracold Rubidium atoms trapped in a periodic optical potential. In such a situation, the most basic interaction between only two atoms at one common potential well, forming a micro laboratory for this atom pair, can be investigated. Spin dependent interactions between the atoms can lead to an intriguing time evolution of the system. In this work, we present two examples of such spin interaction induced dynamics. First, we have been able to observe and control a coherent spin changing interaction. Second, we have \nachieved to examine and manipulate an interaction\ninduced time evolution of the relative phase of a spin 1/2-system, both in the case of particle pairs and in the more general case of N interacting particles. The first part of this thesis elucidates the spin-changing interaction mechanism underlying many fascinating effects resulting from interacting spins at ultracold temperatures. This process changes the spin states of two colliding particles, while preserving total magnetization. If initial and final states have almost equal energy, this process is resonant and leads to large amplitude\noscillations between different spin states. The measured coupling parameters of such a process allow to precisely infer atomic scattering length differences, that e.g. determine the nature of the magnetic ground state of the hyperfine states in Rubidium.\nMoreover, a method to tune the spin oscillations at will based on the AC-Zeeman effect has been implemented. This allowed us to use resonant spin changing \ncollisions as a quantitative and non-destructive particle pair probe in the optical lattice. This led to a series of experiments shedding light on the Bosonic superfluid to Mott insulator transition.\nIn a second series of experiments we have been able to coherently manipulate the interaction induced time evolution of the relative phase in an ensemble of spin 1/2-systems. For two particles, interactions can lead to an entanglement oscillation of the particle pair. For the general case of N interacting particles, the ideal time evolution leads to the creation of spin squeezed states and even Schrödinger cat states. In the experiment we have been able to control the underlying\ninteractions by a Feshbach resonance. For particle pairs we could directly observe the entanglement oscillations. For the many particle case we have been able to observe and reverse the interaction induced dispersion of the relative phase.\nThe presented results demonstrate how correlated spin states can be engineered through \ncontrol of atomic interactions. Moreover, the results point towards the possibility to simulate quantum\nmagnetism phenomena with ultracold atoms in optical traps, and to realize and analyze many novel quantum spin states which have not been experimentally realized so far.