Dynamical polarizability of atoms in arbitrary light fields: general theory and application to cesium

Kien, Fam Le; Schneeweiß, Philipp; Rauschenbeutel, Arno

doi:10.1140/epjd/e2013-30729-x

Cited by 211 publications

(215 citation statements)

References 57 publications

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“…Hence, in our method a set of collisional beams are applied in conjunction with loading from a magneto-optical trap (MOT). Despite this difference, we find the optical detunings and powers required are similar to previous work with 85 Rb [16,21].The experimental apparatus generates optical tweezers by focusing λ = 852 nm light to a 1/e 2 radius of w 0 = 0.71 µm [7,24,25]. Arrays of optical tweezers are created by generating multiple deflections in each of two acousto-optic modulators (AOMs) oriented to generate perpendicular deflections.…”

supporting

confidence: 59%

Rapid Production of Uniformly Filled Arrays of Neutral Atoms

et al. 2015

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We demonstrate rapid loading of a small array of optical tweezers with a single 87 Rb atom per site. We find that loading efficiencies of up to 90% per tweezer are achievable in less than 170 ms for traps separated by more than 1.7 µm. Interestingly, we find the load efficiency is affected by nearby traps and present the efficiency as a function of the spacing between two optical tweezers. This enhanced loading, combined with subsequent rearranging of filled sites, will enable the study of quantum many-body systems via quantum gas assembly.A frontier in atomic physics is the study of quantum many-body physics on a microscopic scale. Recent experiments have shown the power of microscopy of degenerate quantum gases in optical lattices [1,2]. An exciting prospect is not only imaging quantum gases, but assembling them into a well-known initial configuration from single-atom building blocks and then observing the resulting dynamics with single-atom resolution. Wavelength-scale optical dipole traps, or optical tweezers, are an attractive platform for control of neutral atoms because they allow repositioning of the atoms after state preparation and site-resolved imaging. Using optical tweezers, long-range interactions between neutral atoms have been harnessed via Rydberg blockade [3-5], and it is now possible to observe controlled interactions and interference between bosonic and fermionic atoms placed individually in their motional ground state [6][7][8]. While optical tweezer traps can be scaled to arrays [9][10][11][12], realizing an ordered array with a single atom per trap is difficult and is a problem of long-standing interest [13][14][15][16].Early experiments with optical tweezers demonstrated sub-Poissonian atom-number statistics using light-assisted collisions that rapidly expel pairs of atoms, a process known as collisional blockade [17][18][19][20]. This has become a reliable method to isolate single atoms, as well as the basis for parity imaging in quantum-gas microscopes [1,2,17]. However, the collisional blockade also limits loading efficiencies to approximately 50%, making the probability to uniformly-fill large arrays prohibitively small [18][19][20].Careful studies of light-assisted collisions in optical dipole traps hold promise for realizing deterministic loading of arrays of atoms [16,21]. Light-assisted collisions are successfully described by transitions between molecular potentials that become resonant with the light at specific interatomic separations, R C [ Fig. 1(a)] [22]. In the case of light that is red-detuned from the bare atomic transition, the atoms associate to an attractive potential and can gain a large kinetic energy, leading to loss of both atoms from the trap. Conversely, when the light is blue-detuned, the atoms associate to a repulsive potential where the maximum kinetic energy gained is set by the detuning [23]. This control has been used to preferentially expel single 85 Rb atoms from a trap, enabling the isolation of single atoms with high probability [16,21]. However, open q...

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confidence: 59%

Rapid Production of Uniformly Filled Arrays of Neutral Atoms

et al. 2015

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“…These λ zero measurements test theoretical polarizability spectra α(ω) described in references [22][23][24][25][26][27][28][29][30][31][32][33]. To measure λ zero , we apply an irradiance gradient on the paths of a Mach-Zehnder atom beam interferometer [37][38][39].…”

Section: Motivationmentioning

confidence: 88%

“…Tune-out wavelengths occur at roots in the dynamic polarizability spectrum of an atom, and λ zero measurements can serve as benchmark tests of atomic structure calculations [22][23][24][25][26][27][28][29][30][31][32][33]. Here we use decoherence to calibrate the frequency-axis for light-induced phase shift spectra, as we discuss in more detail in Sections 2-4.…”

Section: Introductionmentioning

confidence: 99%

Decoherence Spectroscopy for Atom Interferometry

Trubko

Cronin

2016

Atoms

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Decoherence due to photon scattering in an atom interferometer was studied as a function of laser frequency near an atomic resonance. The resulting decoherence (contrast-loss) spectra will be used to calibrate measurements of tune-out wavelengths that are made with the same apparatus. To support this goal, a theoretical model of decoherence spectroscopy is presented here along with experimental tests of this model.

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“…The large detuning from all atomic and molecular transitions offers low heating and loss rates for the quantum gas. For a laser with intensity I, the total light shifts of atoms (subscript a) and molecules (subscript m) are given by [29] δE a ¼ ðα a þ β a μ a ÞI;where α is the scalar polarizability and the vector polarizability βμ depends on the magnetic moment μ. The brings a molecular energy level (blue surface) close to the atomic scattering threshold (red surface).…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Casting New Light on Atomic Interactions

Vale

2015

Physics

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Optical control of atomic interactions in quantum gases is a long-sought goal of cold atom research. Previous experiments have been hindered by rapid decay of the quantum gas and parasitic deformation of the trap potential. We develop and implement a generic scheme for optical control of Feshbach resonances which yields long quantum gas lifetimes and a negligible parasitic dipole force. We show that fast and local control of interactions leads to intriguing quantum dynamics in new regimes, highlighted by the formation of van der Waals molecules and localized collapse of a Bose condensate. DOI: 10.1103/PhysRevLett.115.155301 PACS numbers: 67.85.-d, 03.75.Kk, 34.50.-s Spatiotemporal control of interactions should bring a plethora of new quantum-mechanical phenomena into the realm of ultracold atom research. Temporal modulation of interactions is theoretically proposed as a route for creating anyonic statistics in optical lattices [1,2] as well as new types of quantum liquids [3,4] and excitations [5][6][7]. Spatial modulation should grant access to unusual soliton behavior [8,9], controlled interfaces between quantum phases [10], stable nonlinear Bloch oscillations [11], and even the dynamics of acoustic black holes [12]. The conventional technique for controlling interactions in cold atoms, magnetic Feshbach resonance [13,14], is typically insufficient for these applications because magnetic coils are generally too large for very fast or local modulation.A promising alternative is optical control of Feshbach resonances (OFR), with which high speed, spatially resolved control of interactions can be realized. Efforts toward achieving OFR in quantum gases have made significant progress [15-28] but have encountered two major obstacles. First, in previous experiments OFR has limited the quantum gas lifetime to the millisecond time scale [24,26,27] due to optical excitation to molecular states. Short lifetimes forbid studies of quantum gases in equilibrium or after typical dynamical time scales. Second, the change of interaction strength from OFR is often accompanied by an optical potential. This potential can result in a parasitic dipole force which dominates the dynamics when the interactions are spatially modulated [21].In this Letter we propose and implement a scheme for optically controlling interactions while maintaining a long quantum gas lifetime and negligible parasitic dipole force. With a far-detuned laser, a change of the scattering length a, which determines the interaction strength, by 180 Bohr radii (a 0 ) is only coupled with a slow radiative loss of 1.6 s −1 . This loss rate is sufficiently low to allow the BEC to remain in equilibrium. Furthermore, the laser operates at a magic wavelength to eliminate the atomic dipole potential. We apply OFR to test the response of Bose-Einstein condensates (BECs) to rapid oscillation of interactions down to the time scale of 10 ns, reaching beyond the van der Waals energy scale. Moreover, by spatially modulating the interaction strength we observe the intriguing...

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Dynamical polarizability of atoms in arbitrary light fields: general theory and application to cesium

Cited by 211 publications

References 57 publications

Rapid Production of Uniformly Filled Arrays of Neutral Atoms

Rapid Production of Uniformly Filled Arrays of Neutral Atoms

Decoherence Spectroscopy for Atom Interferometry

Casting New Light on Atomic Interactions

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