Publisher’s Note: Collective oscillations of a one-dimensional trapped Bose-Einstein gas [Phys. Rev. A<b>66</b>, 043610 (2002)]

Menotti, C.; Stringari, S.

doi:10.1103/physreva.67.069904

Cited by 139 publications

(331 citation statements)

References 0 publications

Supporting

Mentioning

309

Contrasting

Order By: Relevance

“…We then ramp the bias field in 4 s from the initial value to B av = 565 G (where a av ∼ 3 a 0 ). For these experimental values, the dimensionality parameter is λP ≈ 0.3, close to the transition into the quasi-one-dimensional regime (determined by λP 1) [38]. At this point we oscillate the magnetic field with a modulation depth of δB = 14 G, corresponding to δa ∼ 2 a 0 .…”

mentioning

confidence: 99%

Collective excitation of a Bose-Einstein condensate by modulation of the atomic scattering length

Pollack

Dries²,

Hulet³

et al. 2010

Phys. Rev. A

104

113

View full text Add to dashboard Cite

We excite the lowest-lying quadrupole mode of a Bose-Einstein condensate by modulating the atomic scattering length via a Feshbach resonance. Excitation occurs at various modulation frequencies, and resonances located at the natural quadrupole frequency of the condensate and at the first harmonic are observed. We also investigate the amplitude of the excited mode as a function of modulation depth. Numerical simulations based on a variational calculation agree with our experimental results and provide insight into the observed behavior. Collective excitation of a Bose-Einstein condensate (BEC) is an essential diagnostic tool for investigating properties of the ultracold quantum state. Fundamental information about condensate dynamics can be determined from observations of collective modes [1][2][3], including the effects of temperature [4][5][6], and the dimensionality of the system [7]. In addition, the interplay between these modes and external agents, such as random potentials [8,9], lattices [10,11], as well as other atoms [12][13][14][15][16], can be investigated. Examining the excitation spectrum of the BEC allows for a detailed comparison with theoretical models [17][18][19][20] and related quantum systems such as superfluid helium [21,22] and superconductors [23,24].Generically, a collective excitation is generated by the modification of the trapping potential of the condensate [25]. One convenient method is to apply a sudden magnetic field gradient, thereby shifting the center of the trap and exciting a dipole oscillation about the trap center. One may also suddenly change the curvature of the trap to excite quadrupole modes. The lowest-lying m = 0 quadrupole mode is characterized by out-of-phase axial and radial oscillations.If the condensate is not the only occupant of the trap (i.e., there exists a thermal component or another species of atoms) then the other atoms may also be excited through these processes. The evolution of a collective excitation can therefore be complicated because the multiple components may affect damping or induce frequency shifts of the oscillation [12][13][14][15][16]. Therefore, modulating the trap, although an extremely useful tool for an isolated condensate, can be cumbersome when the system to be studied is multispecied. An alternative approach is to excite the condensate alone, leaving the other occupants of the trap untouched.In this work, we demonstrate the excitation of the lowestlying quadrupole mode in a BEC of 7 Li by modulating the atomic scattering length via a magnetic Feshbach resonance. In contrast to abruptly changing the scattering length [26], sinusoidal modulation enables the controlled excitation of a single mode at a specific frequency. In addition, by using this method, a coexisting thermal component will be minimally excited by the mean-field coupling to the normal gas [27,28]. In the case of a multispecies experiment, resonant modulation of the scattering length of one species will not necessarily excite the others, depending on the details of other F...

show abstract

mentioning

confidence: 99%

Collective excitation of a Bose-Einstein condensate by modulation of the atomic scattering length

Pollack

Dries²,

Hulet³

et al. 2010

Phys. Rev. A

104

113

View full text Add to dashboard Cite

show abstract

“…In this expression, a s = 5.3 nm is the (3D) atomic scattering length and n 1D is the linear density (n 1D = F /v ≃ 45 at.µm −1 at v = 9 mm.s −1 ). For n 1D a s < 1 we are in the "1D mean field" regime [26], where the mean-field intralaser interaction may influence the longitudinal dynamics but not the transverse one.…”

mentioning

confidence: 99%

Guided Quasicontinuous Atom Laser

et al. 2006

View full text Add to dashboard Cite

We report the first realization of a guided quasicontinuous atom laser by rf outcoupling a BEC, from a hybrid optomagnetic trap into a horizontal atomic waveguide. This configuration allows us to cancel the acceleration due to gravity and keep the de Broglie wavelength constant at 0.5 µm during 0.1 s of propagation. We also show that our configuration, equivalent to pigtailing an optical fiber to a (photon) semiconductor laser, ensures an intrinsically good transverse mode matching.PACS numbers: 03.75. Pp, 39.20.+q, 42.60.Jf,41.85.Ew The Bose-Einstein condensation of atoms in the lowest level of a trap represents the matter-wave analog to the accumulation of photons in a single mode of a laser cavity. In analogy to photonic lasers, atom lasers can be obtained by outcoupling from a trapped Bose-Einstein condensate (BEC) to free space [1,2,3]. However, since atoms are massive particles, gravity plays an important role in the laser properties: in the case of rf outcouplers, it lies at the very heart of the extraction process [4] and in general, the beam is strongly accelerated downwards, causing a rapid decrease of the de Broglie wavelength. With the growing interest in coherent atom sources for atom interferometry [5,6,7] and new studies of quantum transport phenomena [8,9,10,11,12,13,14] where large and well defined de Broglie wavelength are desirable, a better control of the atomic motion during its propagation is needed. One solution is to couple the atom laser into a horizontal waveguide, so that the effect of gravity is canceled, leading to the realization of a coherent matter wave with constant wavelength.We report in this letter on the realization of such a guided quasicontinuous atom laser, where the coherent source, i.e. the trapped BEC, and the guide are merged together in a hybrid combination of a magnetic Ioffe-Pritchard trap and a horizontally elongated far offresonance optical trap constituting an atomic waveguide (see Fig. 1). The BEC, in a state sensitive to both trapping potentials, is submitted to a rf outcoupler yielding atoms in a state sensitive only to the optical potential, resulting in an atom laser propagating along the weak confining axis of the optical trap. In addition to canceling the effect of gravity, this configuration has several advantages. Firstly, coupling into a guide from a BEC rather than from a thermal sample [15] allows us to couple a significant flux into a small number of transverse modes of the guide. Secondly, the weak longitudinal trapping potential of the guide can be compensated by the antitrapping potential due to the second order Zeeman effect acting onto the outcoupled atoms, resulting in an atom laser with a quasiconstant de Broglie wavelength. Thirdly, using an rf outcoupler rather than releasing a BEC into a guide [14,16] results into quasicontinuous operation, thus insuring sharp linewidth, and gives a better control on the beam parameters. Indeed, changing the frequency of the outcoupler allows one to tune the value of the de Broglie wavelength of the atom...

show abstract

“…Importantly, at ε dd = 1 the overall contact interactions vanish and the TF cigar criterion (17) cannot be satisfied. When ε dd = 0 we retrieve the results of [17].…”

mentioning

confidence: 99%

“…Menotti and Stringari [17] analysed the crossover between the 3D TF and 1D mean-field regimes of a cigar-shaped s-wave BEC. We now extend their approach to include dipolar interactions.…”

mentioning

confidence: 99%

Thomas-Fermi versus one- and two-dimensional regimes of a trapped dipolar Bose-Einstein condensate

Parker

O’Dell

2008

Phys. Rev. A

View full text Add to dashboard Cite

We derive the criteria for the Thomas-Fermi regime of a dipolar Bose-Einstein condensate in cigar, pancake and spherical geometries. This also naturally gives the criteria for the mean-field one-and two-dimensional regimes. Our predictions, including the Thomas-Fermi density profiles, are shown to be in excellent agreement with numerical solutions. Importantly, the anisotropy of the interactions has a profound effect on the Thomas-Fermi/low-dimensional criteria.PACS numbers: 03.75. Hh, 75.80.+q Introduction. A Bose-Einstein condensate (BEC) is said to be in the Thomas-Fermi (TF) regime when the interaction energy dominates the zero-point energy [1,2]. Despite being a dilute gas, in this regime the BEC is strongly affected by interactions and behaves in a highly non-ideal manner. Furthermore, the TF description is relatively simple compared to full Gross-Pitaevskii theory and facilitates exact results [1]. Consider a BEC containing N atoms of mass m confined to a spherical harmonic trap V (r) = mω 2 r 2 /2, with harmonic oscillator (HO) length l ho = /(mω), and repulsive s-wave interactions with positive scattering length a. The TF regime occurs for large values of the parameter N a/l ho , and thus typically arises for dense strongly repulsive BECs.Recently, a dipolar BEC was created with atomic dipoles polarized in a common direction by an external field [3]. Far from any scattering resonances the interaction can be represented by a pseudo-potential which includes the bare dipole-dipole interaction [4,5],

show abstract

Publisher’s Note: Collective oscillations of a one-dimensional trapped Bose-Einstein gas [Phys. Rev. A66, 043610 (2002)]

Cited by 139 publications

References 0 publications

Collective excitation of a Bose-Einstein condensate by modulation of the atomic scattering length

Collective excitation of a Bose-Einstein condensate by modulation of the atomic scattering length

Guided Quasicontinuous Atom Laser

Thomas-Fermi versus one- and two-dimensional regimes of a trapped dipolar Bose-Einstein condensate

Contact Info

Product

Resources

About