arXiv subjects

D. Delande

Publications and source records attributed to D. Delande.

21 records · Page 2Linked to original sources

arXiv2002

Coherent light transport in a cold Strontium cloud

We study light coherent transport in the weak localization regime using magneto-optically cooled strontium atoms. The coherent backscattering cone is measured in the four polarization channels using light resonant with a J=0 to J=1 transition of the Strontium atom. We find an enhancement factor close to 2 in the helicity preserving channel, in agreement with theoretical predictions. This observation confirms the effect of internal structure as the key mechanism for the contrast reduction observed with an Rubidium cold cloud (see: Labeyrie et al., PRL 83, 5266 (1999)). Experimental results are in good agreement with Monte-Carlo simulations taking into account geometry effects.

physics.atom-ph↗

arXiv2000

Chaos assisted tunnelling with cold atoms

In the context of quantum chaos, both theory and numerical analysis predict large fluctuations of the tunnelling transition probabilities when irregular dynamics is present at the classical level. We consider here the non-dissipative quantum evolution of cold atoms trapped in a time-dependent modulated periodic potential generated by two laser beams. We give some precise guidelines for the observation of chaos assisted tunnelling between invariant phase space structures paired by time-reversal symmetry.

nlin.CD↗

arXiv1998

Spectral properties of non-hydrogenic atoms in weak external fields

We study how the ionic core in a non-hydrogenic atom modifies the dynamics of a Rydberg electron in the presence of a weak static external field. We show that such a system is neither regular nor chaotic: its energy levels display unusual statistical properties, intermediate between the standard Poisson and Random Matrix ones. The ionic core acts as a scatterer whose size is comparable to the de Broglie wavelength of the electron, inducing specific quantum effects.

chao-dyn↗