Stabilization of a purely dipolar quantum gas against collapse
By T. Koch, T. Lahaye, J. Metz, B. Fröhlich, A. Griesmaier, Tilman Pfau. 2007
281 citations recorded by the source corpus.
For the first time, a purely dipolar quantum gas has been prepared experimentally. Different regimes have been explored; in some, the gas is stable, whereas in others it collapses due to the strong dipole–dipole interaction between the constituent atoms. Although the phenomenon of Bose–Einstein condensation1 is a purely statistical effect that also appears in an ideal gas, the physics of Bose–Einstein condensates (BECs) of dilute gases is considerably enriched by the presence of interactions among the atoms. In usual experiments with BECs, the only relevant interaction is the isotropic and short-range contact interaction, which is described by a single parameter, the scattering length a. In contrast, the dipole–dipole interaction between particles possessing an electric or magnetic dipole moment is of long-range character and anisotropic, which gives rise to new phenomena2,3. Most prominently, the stability of a dipolar BEC depends not only on the value of the scattering length, a, but also strongly on the geometry of the external trapping potential4,5,6,7. Here, we report on the experimental investigation of the stability of a dipolar BEC of 52Cr as a function of the scattering length and the trap aspect ratio. We find good agreement with a universal stability threshold arising from a simple theoretical model. Using a pancake-shaped trap with the dipoles oriented along the short axis of the trap, we are able to tune the scattering length to zero, stabilizing a purely dipolar quantum gas.
Subfields: Atomic and Molecular Physics, and Optics
View Paper: https://www.semanticscholar.org/paper/eef74d4fbbee9a664cad5e311118f532c5efac2c
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In Atomic and Molecular Physics, and Optics
Citations in the corpus
- Theoretical progress in many-body physics with ultracold dipolar gases (2008, background): “Recent successful realization and studies of Bose–Einstein condensation of 52Cr atoms [1–7] and progress in trapping and cooling of polar molecules [8–19] stimulated great interest in the properties of dipolar systems at low temperatures.”
- Spinor Bose-Einstein condensates (2010, methodology): “lkali atoms is a thousandtimes smaller than the short-range interaction for the background scattering length. However, recent experimental developments, such as the realization of a BEC of 52Cr atoms [15, 16, 17, 18, 19, 20], a technique for creating cold molecular gases [21, 22, 23], and high-accur”
- Dipole blockade in a cold Rydberg atomic sample [Invited] (2010, background): “Similar dipole-dipole studies can be performed using cold polar molecules [108, 109, 110, 111, 112] or magnetic dipolar gases, such as beautifully observed in strongly perturbed anisotropic expansion of a Chromium condensate by Tilman Pfau’s group [113, 114].”
- Taming molecular beams (2008, background): “The anisotropic long-range dipole-dipole interaction is predicted to give rise to new and rich physics in these cold dipolar gases [65–67], as has already been observed in a Bose-Einstein condensate of Chromium atoms with strong magnetic dipole-dipole interactions [68, 69].”
- Feshbach resonances in ultracold gases (2008, background): “, 2008) investigated the controlled collapse of the system and demonstrated its complex dynamics and (Koch et al., 2008) studied the stability of the dipolar condensate depending on the trap geometry.”
- Rotating trapped Bose-Einstein condensates (2008, methodology): “ng the zˆ direction. Such fields lead to the simpler interaction potential [see, for example, the review by Menotti and Lewenstein (2007) and the experimental studies of 52Cr (Griesmaier et al., 2005; Koch et al., 2007; Lahaye et al., 2007)] Vdd(r −r′) = d2 |r −r′|3 h 1−3(zˆ· nˆ)2 i , (7.1) where dis”