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

Atomic motion in an optical lattice

Natalya V. Morrow

Published Jan 1, 2006• 1 citation
OpenAlex

Abstract

Optical lattices are periodic light shift potentials that are created by the interference of several laser beams. In this dissertation I investigate the motion of atoms in such potentials. The center-of-mass wave-packet motion is initiated by an application of a sudden shift to the lattice potentials. The resulting oscillations are observed using a photon redistribution technique. We first show that by utilizing a real-time feedback loop and shifting the lattice continuously in response to the wave-packet motion, we can increase, alter or damp this motion using different gains of the feedback loop. We further show that by splitting the wave-packet between two adiabatic potentials of the lattice via quantum projection, we can construct an atom interferometer. We observe interference signal when the two components of the original wave-packet overlap. The behavior of the interference is studied as a function of lattice parameters and a consistent theoretical picture is developed. Further, we study how well-to-well tunneling of atoms and sloshing-type wave-pocket dynamics affect each other. We find that in the regions where the well-to-well tunneling is significant, the sloshing type wave-packet oscillations are suppressed. Sloshing-type motion only occurs if the tunneling is sufficiently suppressed with an applied magnetic field. Finally we describe a new type of optical lattice that is based on two-photon Raman transitions. The basic period of this lattice is reduced by a factor of two, compared with traditional lattices. We also show that Sub-Doppler cooling mechanism is present in this lattice. The dissertation is concluded with the presentation of a new experimental set-up for Bose-Einstein Condensate production, which may in the future be used for the study of BEC dynamics in optical lattices.

Related papers

Coherent effects and enhanced cooling in optical lattices.

Subrata Dutta

Optical lattices are periodic arrangements of laser cooled atoms trapped in potentials created by the interference of multiple laser beams. In this dissertation, we describe a series of experiments performed using optical lattices that exploit the coherence of atoms and we also look at new ways to cool the atoms. With a sudden shift of the optical lattice, atomic wavepackets can be created that evolve much like a classical particle. Using a photon redistribution technique, we have characterized the oscillation of wavepackets in the anharmonic potential wells. Atoms will quantum mechanically tunnel between lattice sites with a sufficiently shallow potential. Due to the structure of the optical lattices that are used, while the atom is tunneling, its internal angular momentum state must change. We use this change to detect and characterize the tunneling. The change in internal state leads to the formation of a new potential that acts on the atom, which is known as a gauge potential, which does not depend on the light intensity, but depends only on the geometry of the lattice. We have for the first time measured and characterized this gauge potential. Finally, by randomly modulating the lattice potential, we have demonstrated that tunneling can be suppressed. We have shown that an enhancement of the Sisyphus cooling process, which localizes atoms in the wells of an optical lattice, is possible using a bichromatic standing wave. A time of flight technique is used to verify the cooling improvement. We combine the techniques developed in these experiments and apply them to the cooling of the trapped atoms using a feedback mechanism, which is analogous to the well known technique of stochastic cooling in the field of beam physics. Lastly, we have laid the theoretical basis for using the ponderomotive force to create optical lattices for laser cooled Rydberg atoms. Rydberg atoms are attractive because of their many extreme properties, and the ability to trap Rydberg atoms into lattice sites will increase the range of experiments and measurements that can be made with them.

•Jan 1, 2000•0 citations

Cold neutral atoms in optical lattices

Rui Zhang

In this thesis, I study the properties of cold neutral atoms, including Bose-Einstein condensates (BEC), inside periodic light-shift potentials created by optical lattices. In the first part, a new optical-lattice scheme, employing Raman transitions, hereafter referred to as a Raman Optical Lattice (ROL), is investigated. This optical lattice possesses a novel sub-Doppler cooling mechanism and a reduced periodicity. Both theoretical and experimental results con¯rm these two characteristics of the ROL. In the second half of the thesis, instead of thermal atoms, optical lattices are loaded with condensate atoms. Our BEC apparatus and the procedure towards forming a BEC are described in detail. After the achievement of the BEC, a 1D far-detuned optical lattice is applied to the BEC. A number of phenomena are observed, including Kapitza-Dirac diffraction, thermal atom interference, atom interferometry, Bloch oscillations, and a superfluid to Mott-insulator transition. Finally a brief discussion about future work is given.

•Jan 1, 2008•1 citation

Decay of Atomic Wave-Packet Motion in Optical Lattices

Georg A. Raithel, William D. Phillips, S. L. Rolston

We study, experimentally and with quantum Monte-Carlo wave-function simulations, the effects of dispersion and dissipation on two types of spatial wave-packets of atoms in 1D and 3D optical lattices. Breathing-mode oscillations are excited by suddenly changing the potential depth after equilibration of the atoms at the lattice sites. The subsequent breathing-mode oscillations are measured using Bragg scattering. The second type of oscillations is prepared by suddenly shifting the lattice, thus exciting coherent-state-like wave-packets. These sloshing-type oscillations manifest themselves in a periodic photon redistribution between the lattice beams. We measure the resultant intensity exchange, which is a sensitive probe for the wave-packet evolution. For both types of wave-packets we observe an initial collapse within about three to six oscillation periods, a fact which we attribute to dephasing of the components of the wave-packets caused by the anharmonicity of the lattice potential. The initial collapse is followed by revivals of the wave-packets. Dissipation not only reduces the amplitude of these revivals but also modifies their shape and time of occurrence. In shallow lattices we observe that tunneling of the atoms between neighboring potential wells influences the wave-packet oscillations.

Fortschritte der Physik•Nov 1, 1998•1 citation

Quantum tunneling and coherent wavepacket dynamics in an optical lattice

D. L. Haycock

This dissertation reports on the experimental study of coherent wavepacket dynamics of cesium atoms in the double-well potentials of a one-dimensional, far-off-resonance optical lattice. An optical lattice is the periodic potential produced by the light shift interaction of an atom with the light field of interfering laser beams. With the proper choice of laser parameters and external magnetic fields, an array of double-well potentials is created. Using the techniques of laser cooling, atoms are trapped in the lattice and are prepared in a pure state through a combination of enhanced laser cooling in a near-resonance lattice and state selection in an accelerated far-off-resonance lattice. The atoms are prepared on one side of the double-well potential, and the atomic wavepackets will then oscillate between the left and right localized states of the double-well potential. Entanglement between the internal and external degrees of freedom makes it possible to follow the center-of-mass motion of the atoms by measuring the ground state magnetic populations via Stern-Gerlach analysis. The coherent dynamics of these wavepackets was studied under various combinations of lattice parameters such as lattice depth, applied transverse and longitudinal magnetic fields. There is excellent agreement between the experimentally measured oscillation frequencies and those predicted from a numerical analysis of the bandstructure of the lattice. For certain lattice parameters the total energy of the atom is below the potential barrier and the coherent motion corresponds to tunneling through a classically forbidden barrier. At specific times during the oscillation the atomic wavepacket corresponds to a coherent superposition of the mesoscopically distinct left and right localized states.

•Jan 1, 2000•1 citation

Feedback Control of Atomic Motion in an Optical Lattice

Natalya V. Morrow, S. K. Dutta, Georg A. Raithel

We demonstrate a real-time feedback scheme to manipulate wave-packet oscillations of atoms in an optical lattice. The average position of the atoms in the lattice wells is measured continuously and nondestructively. A feedback loop processes the position signal and translates the lattice potential. Depending on the feedback loop characteristics, we find amplification, damping, or an entire alteration of the wave-packet oscillations. Our results are well supported by simulations.

Physical Review Letters•Feb 15, 2002•71 citations

Collapse and Revivals of Wave Packets in Optical Lattices

Georg A. Raithel, William D. Phillips, S. L. Rolston

We study the effects of dispersion, tunneling, and dissipation on wave-packet oscillations resembling coherent states of atoms in optical lattices. The wave packets are prepared by suddenly shifting the lattice after equilibration of the atoms at the lattice sites. The atoms oscillate in the light-shift potential wells, which exert a force arising from photon redistribution between lattice beams. We measure the resultant periodic intensity exchange between the beams, obtaining information on the wave-packet evolution. We observe a strong impact of dissipation on the overall shape and the time of revivals, as well as a suppression of tunneling by weak magnetic fields.

Physical Review Letters•Oct 26, 1998•86 citations
Optical lattices are periodic light shift potentials that are created by the interference of several laser beams. In this dissertation I investigate the motion of atoms in such potentials. The center-of-mass wave-packet motion is initiated by an application of a sudden shift to the lattice potentials. The resulting oscillations are observed using a photon redistribution technique. We first show that by utilizing a real-time feedback loop and shifting the lattice continuously in response to the wave-packet motion, we can increase, alter or damp this motion using different gains of the feedback loop. We further show that by splitting the wave-packet between two adiabatic potentials of the lattice via quantum projection, we can construct an atom interferometer. We observe interference signal when the two components of the original wave-packet overlap. The behavior of the interference is studied as a function of lattice parameters and a consistent theoretical picture is developed. Further, we study how well-to-well tunneling of atoms and sloshing-type wave-pocket dynamics affect each other. We find that in the regions where the well-to-well tunneling is significant, the sloshing type wave-packet oscillations are suppressed. Sloshing-type motion only occurs if the tunneling is sufficiently suppressed with an applied magnetic field. Finally we describe a new type of optical lattice that is based on two-photon Raman transitions. The basic period of this lattice is reduced by a factor of two, compared with traditional lattices. We also show that Sub-Doppler cooling mechanism is present in this lattice. The dissertation is concluded with the presentation of a new experimental set-up for Bose-Einstein Condensate production, which may in the future be used for the study of BEC dynamics in optical lattices.
Optical lattices are periodic arrangements of laser cooled atoms trapped in potentials created by the interference of multiple laser beams. In this dissertation, we describe a series of experiments performed using optical lattices that exploit the coherence of atoms and we also look at new ways to cool the atoms. With a sudden shift of the optical lattice, atomic wavepackets can be created that evolve much like a classical particle. Using a photon redistribution technique, we have characterized the oscillation of wavepackets in the anharmonic potential wells. Atoms will quantum mechanically tunnel between lattice sites with a sufficiently shallow potential. Due to the structure of the optical lattices that are used, while the atom is tunneling, its internal angular momentum state must change. We use this change to detect and characterize the tunneling. The change in internal state leads to the formation of a new potential that acts on the atom, which is known as a gauge potential, which does not depend on the light intensity, but depends only on the geometry of the lattice. We have for the first time measured and characterized this gauge potential. Finally, by randomly modulating the lattice potential, we have demonstrated that tunneling can be suppressed. We have shown that an enhancement of the Sisyphus cooling process, which localizes atoms in the wells of an optical lattice, is possible using a bichromatic standing wave. A time of flight technique is used to verify the cooling improvement. We combine the techniques developed in these experiments and apply them to the cooling of the trapped atoms using a feedback mechanism, which is analogous to the well known technique of stochastic cooling in the field of beam physics. Lastly, we have laid the theoretical basis for using the ponderomotive force to create optical lattices for laser cooled Rydberg atoms. Rydberg atoms are attractive because of their many extreme properties, and the ability to trap Rydberg atoms into lattice sites will increase the range of experiments and measurements that can be made with them.
In this thesis, I study the properties of cold neutral atoms, including Bose-Einstein condensates (BEC), inside periodic light-shift potentials created by optical lattices. In the first part, a new optical-lattice scheme, employing Raman transitions, hereafter referred to as a Raman Optical Lattice (ROL), is investigated. This optical lattice possesses a novel sub-Doppler cooling mechanism and a reduced periodicity. Both theoretical and experimental results con¯rm these two characteristics of the ROL. In the second half of the thesis, instead of thermal atoms, optical lattices are loaded with condensate atoms. Our BEC apparatus and the procedure towards forming a BEC are described in detail. After the achievement of the BEC, a 1D far-detuned optical lattice is applied to the BEC. A number of phenomena are observed, including Kapitza-Dirac diffraction, thermal atom interference, atom interferometry, Bloch oscillations, and a superfluid to Mott-insulator transition. Finally a brief discussion about future work is given.
We study, experimentally and with quantum Monte-Carlo wave-function simulations, the effects of dispersion and dissipation on two types of spatial wave-packets of atoms in 1D and 3D optical lattices. Breathing-mode oscillations are excited by suddenly changing the potential depth after equilibration of the atoms at the lattice sites. The subsequent breathing-mode oscillations are measured using Bragg scattering. The second type of oscillations is prepared by suddenly shifting the lattice, thus exciting coherent-state-like wave-packets. These sloshing-type oscillations manifest themselves in a periodic photon redistribution between the lattice beams. We measure the resultant intensity exchange, which is a sensitive probe for the wave-packet evolution. For both types of wave-packets we observe an initial collapse within about three to six oscillation periods, a fact which we attribute to dephasing of the components of the wave-packets caused by the anharmonicity of the lattice potential. The initial collapse is followed by revivals of the wave-packets. Dissipation not only reduces the amplitude of these revivals but also modifies their shape and time of occurrence. In shallow lattices we observe that tunneling of the atoms between neighboring potential wells influences the wave-packet oscillations.
This dissertation reports on the experimental study of coherent wavepacket dynamics of cesium atoms in the double-well potentials of a one-dimensional, far-off-resonance optical lattice. An optical lattice is the periodic potential produced by the light shift interaction of an atom with the light field of interfering laser beams. With the proper choice of laser parameters and external magnetic fields, an array of double-well potentials is created. Using the techniques of laser cooling, atoms are trapped in the lattice and are prepared in a pure state through a combination of enhanced laser cooling in a near-resonance lattice and state selection in an accelerated far-off-resonance lattice. The atoms are prepared on one side of the double-well potential, and the atomic wavepackets will then oscillate between the left and right localized states of the double-well potential. Entanglement between the internal and external degrees of freedom makes it possible to follow the center-of-mass motion of the atoms by measuring the ground state magnetic populations via Stern-Gerlach analysis. The coherent dynamics of these wavepackets was studied under various combinations of lattice parameters such as lattice depth, applied transverse and longitudinal magnetic fields. There is excellent agreement between the experimentally measured oscillation frequencies and those predicted from a numerical analysis of the bandstructure of the lattice. For certain lattice parameters the total energy of the atom is below the potential barrier and the coherent motion corresponds to tunneling through a classically forbidden barrier. At specific times during the oscillation the atomic wavepacket corresponds to a coherent superposition of the mesoscopically distinct left and right localized states.
We study the effects of dispersion, tunneling, and dissipation on wave-packet oscillations resembling coherent states of atoms in optical lattices. The wave packets are prepared by suddenly shifting the lattice after equilibration of the atoms at the lattice sites. The atoms oscillate in the light-shift potential wells, which exert a force arising from photon redistribution between lattice beams. We measure the resultant periodic intensity exchange between the beams, obtaining information on the wave-packet evolution. We observe a strong impact of dissipation on the overall shape and the time of revivals, as well as a suppression of tunneling by weak magnetic fields.