Searcharxiv⌕ Search

arXiv · physics/0306095

Deterministic instabilities in the magneto-optical trap

Abstract

The cloud of cold atoms obtained from a magneto-optical trap is known to exhibit two types of instabilities in the regime of high atomic densities: stochastic instabilities and deterministic instabilities. In the present paper, the experimentally observed deterministic dynamics is described extensively. Three different behaviors are distinguished. All are cyclic, but not necessarily periodic. Indeed, some instabilities exhibit a cyclic behavior with an erratic return time. A one-dimensional stochastic model taking into account the shadow effect is shown to be able to reproduce the experimental behavior, linking the instabilities to a several bifurcations. Erraticity of some of the regimes is shown to be induced by noise.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Andrea Di Stefano, Philippe Verkerk, Daniel Hennequin. 2003-06-12. Deterministic instabilities in the magneto-optical trap. https://doi.org/10.1140/epjd%2Fe2004-00089-y

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Independent nuclear charge radius determinations: bound-electron $g$ factor versus muonic atom spectroscopy

We present an alternative method to determine absolute nuclear charge radii competitively via the bound electron $g$ factor of H-like ions. The method is demonstrated for $^{118}$Sn by extracting its radius with a precision of 0.1%. This is the second most precise radius ever determined from an electronic system. We benchmark our result against a state-of-the-art value derived from the spectrum of muonic $^{118}$Sn. This comparison reveals a 3.2$σ$ tension, prompting a careful reexamination of the calculations and calling for additional measurements. Crucially, after decades, we now have two independent methods to measure absolute charge radii with similar precision.

physics.atom-ph↗

Energies and lifetimes of the 9p and 10p excited states in atomic francium

We present the first measurement of 9p 2P1/2,3/2 and 10p 2P1/2,3/2 excited levels absolute wavenumbers and radiative lifetime in francium. We used the Collinear Resonance Ionization Spectroscopy (CRIS) technique, applied on a beam of 221Fr atoms. Prior to this work, no experimental data existed for francium p-states with n > 8. The results provide a precision experimental test of relativistic coupled-cluster theory for the heaviest alkali, showing good agreement for lifetimes and relative excitation energies, despite a residual global offset in absolute energies.

physics.atom-ph↗

Switching off a high-harmonic polarization channel by anti-unitary symmetry

We study polarization-resolved high-harmonic generation in a laser-driven two-leg Su--Schrieffer--Heeger ladder with asymmetric dimerization under periodic boundary conditions. A field linearly polarized along the ladder can generate both longitudinal and transverse radiation, whose harmonic content is controlled by lattice symmetry and electronic filling. Using symmetry analysis of the time-dependent density matrix, we show that reflection symmetry enforces odd-order harmonics in the longitudinal response and, when the transverse response is nonzero, even-order harmonics in the transverse direction. At half filling, an additional anti-unitary symmetry relating the occupied and empty bands suppresses the transverse current completely. A unitary chiral symmetry in the clean ladder relates the same bands but fails to enforce this cancellation, showing that band swapping alone is insufficient: the suppression requires both a density-matrix constraint that persists during the driven evolution and the appropriate transformation of the transverse-current operator. Moving away from half filling lifts this cancellation and allows transverse emission, while the reflection selection rule remains whenever reflection symmetry is preserved. Numerical calculations at quarter and half filling, combined with onsite potentials that selectively break the relevant symmetries, confirm these two distinct mechanisms. Thus, reflection symmetry determines which harmonic orders occur, whereas the interplay of anti-unitary symmetry and filling controls whether the transverse HHG channel is present at all.

physics.atom-ph↗