arXiv subjects

L. M. Castellano

Publications and source records attributed to L. M. Castellano.

3 recordsLinked to original sources

arXiv2002

IR control of atoms laser instability

In this paper we show how to control the quantum laser atoms instability using IR radiation. The control can be achieved by controlling the scattering length constant via the infrared coupling constant. This method is applied in the scheme of a continuous CW laser and involves three occupation levels in the condensed atoms.This atoms in Lambda configuration the description of which is given by a Reformed Gross-Pitaevskii equation (RGPE), together with a rate equation.The system is taken to a nonconservative complex Ginzburg Landau equation (CGLE) description from where we use the Benjamin-Feir stability criterium.This method allows us a theoretical construction of any atom laser even for negative interaction constant as is the case of $^{7}Li$.

quant-ph↗

arXiv2001

Temporal Windowing of Trapped States

Trapped state definition for 3-level atoms in Lambda configuration, is a very restrictive one, and for the case of unpolarized beams, this definition no longer holds.We introduce a more general definition by using a reference frame rotating with the frequency of the control field, obtaining a temporal windowing for the trapped population.This amounts to a time quantization of the coherent population transfer, making possible to study the phase coherence in trapped light.

quant-ph↗

arXiv1999

Dissipative Dynamics of an Open Bose Einstein Condensate

As an atomic Bose Einstein condensate (BEC) is coupled to a source of uncondensed atoms at the same temperature and to a sink (extraction towards an atom laser) the idealized description in terms of a Gross-Pitaevsky equation (GP) no longer holds. Under suitable physical assumptions we show that the dissipative BEC obeys a Complex Ginzburg Landau equation (CGL) and for some parameter range it undergoes a space time patterning. As a consequence, the density of BEC atoms within the trap displays non trivial space time correlations, which can be detected by monitoring the density profile of the outgoing atom laser. The patterning condition requires a negative scattering length, as e.g. in $^7$Li. In such a case we expect a many domain collapsed regime, rather than a single one as reported for a closed BEC.

cond-mat.mes-hall↗