Experimental Studies Of Bose-Einstein Condensates In Sodium

Ketterle, Wolfgang

doi:10.1007/0-306-47103-5_1

Cited by 8 publications

(10 citation statements)

References 59 publications

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“…At sufficiently low temperatures, particles in a dilute boson gas condense in the ground state, forming a Bose-Einstein condensate (BEC). This was first observed experimentally in 1995 in Na and Rb vapors [37,16,26,12].…”

Section: Introductionmentioning

confidence: 60%

Resonant and non-resonant modulated amplitude waves for binary Bose–Einstein condensates in optical lattices

Porter

Malomed

2004

Physica D: Nonlinear Phenomena

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We consider a system of two Gross-Pitaevskii (GP) equations, in the presence of an optical-lattice (OL) potential, coupled by both nonlinear and linear terms. This system describes a Bose-Einstein condensate (BEC) composed of two different spin states of the same atomic species, which interact linearly through a resonant electromagnetic field. In the absence of the OL, we find plane-wave solutions and examine their stability. In the presence of the OL, we derive a system of amplitude equations for spatially modulated states which are coupled to the periodic potential through the lowest-order subharmonic resonance. We determine this averaged system's equilibria, which represent spatially periodic solutions, and subsequently examine the stability of the corresponding solutions with direct simulations of the coupled GP equations. We find that symmetric (equalamplitude) and asymmetric (unequal-amplitude) dual-mode resonant states are, respectively, stable and unstable. The unstable states generate periodic oscillations between the two condensate components, which is possible only because of the linear coupling between them. We also find four-mode states, but they are always unstable. Finally, we briefly consider ternary (three-component) condensates.

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Section: Introductionmentioning

confidence: 60%

Resonant and non-resonant modulated amplitude waves for binary Bose–Einstein condensates in optical lattices

Porter

Malomed

2004

Physica D: Nonlinear Phenomena

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“…If we take the quantization axis Þ along the long axis of the condensate (which is also the We now discuss the existence of superradiant gain for such a Raman process. For Rayleigh scattering an expression has been derived both semiclassically and quantum-mechanically, using descriptions based on either atomic or optical stimulation [7,12,14]:…”

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confidence: 99%

Raman amplification of matter waves

et al. 2004

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We demonstrate a Raman amplifier for matter-waves, where the amplified atoms and the gain medium are in two different hyperfine states. This amplifier is based on a novel form of superradiance that arises from self-stimulated Raman scattering in a Bose-Einstein condensate. 42.50.Ct, 42.50.Gy With the realization of coherent, laser-like atoms in the form of Bose-Einstein condensates it has become possible to explore matter-wave amplification, a process in which the number of atoms in a quantum state is amplified due to bosonic stimulation. Stimulation has been observed in the formation of condensates [1,2] and, more directly, has been used to realize coherent matter-wave amplifiers [3,4] based on superradiant Rayleigh scattering [5][6][7][8][9][10][11][12][13] in which the atomic momentum of the gain medium and the amplified atoms differ by a photon recoil. In these cases the atoms remained in the same internal state, a fact that severely limited the performance of superradiant atom amplifiers since the amplified atoms were scattered out of the final state or served as a gain medium for higher-order processes (superradiant cascades [7]).In this Letter we demonstrate a Raman atom amplifier in which the gain medium and the amplified atoms are in different internal states. Such a system has analogies to an optical laser in which different transitions are used for pumping and lasing, thus circumventing the above limitations. The gain mechanism for this amplifier is stimulated Raman scattering in a £-type atomic level structure which occurs in a superradiant way. This system also acts as a Stokes Raman laser for optical radiation.The amplification scheme is similar to that explored in previous work on Rayleigh superradiance in Bose-Einstein condensates [7,12] (cf. fig. 1 A). A linearly polarized laser beam with wavevector is incident on a magnetically trapped, cigar-shaped condensate, perpendicular to its long axis. Each scattering event creates a scattered photon with momentum

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“…At low temperatures, particles in a dilute gas can reside in the same quantum (ground) state, forming a Bose-Einstein condensate. 15,23,33,43 This was first observed experimentally in 1995 with vapors of rubidium and sodium. 4,24 In these experiments, atoms were confined in magnetic traps, evaporatively cooled to tempuratures on the order of fractions of microkelvins, left to expand by switching off the confining trap, and subsequently imaged with optical methods.…”

Section: Introductionmentioning

confidence: 84%

“…At low temperatures, particles in a gas can reside in the same quantum (ground) state, forming a Bose-Einstein condensate [3,10,16,17,24,31]. When considering only two-body, mean-field interactions, the condensate wavefunction ψ satisfies the Gross-Pitaevskii (GP) equation, a cubic nonlinear Schrödinger equation (NLS) with an external potential:…”

mentioning

confidence: 99%

A perturbative analysis of modulated amplitude waves in Bose–Einstein condensates

Porter

Cvitanović

2004

Chaos: An Interdisciplinary Journal of Nonlinear Science

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We apply Lindstedt's method and multiple scale perturbation theory to analyze spatio-temporal structures in nonlinear Schrödinger equations and thereby study the dynamics of quasi-one-dimensional BoseEinstein condensates (BECs) with mean-field interactions. We determine the dependence of the intensity of modulated amplitude waves (MAWs) on their wave number. We also explore BEC band structure in detail using Hamiltonian perturbation theory and supporting numerical simulations.

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Experimental Studies Of Bose-Einstein Condensates In Sodium

Cited by 8 publications

References 59 publications

Resonant and non-resonant modulated amplitude waves for binary Bose–Einstein condensates in optical lattices

Resonant and non-resonant modulated amplitude waves for binary Bose–Einstein condensates in optical lattices

Raman amplification of matter waves

A perturbative analysis of modulated amplitude waves in Bose–Einstein condensates

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