[institut] Podsetnik, danas je SCL seminar: Faraday waves in BECs, Antun Balaz, petak 24. maj u 14:00

[Nenad Vukmirovic]

Postovane koleginice i kolege,

Podsecam vas da ce se danas odrzati dole najavljeni seminar.

Srdacan pozdrav,

-- 
Dr Nenad Vukmirovic,
Visi naucni saradnik,
Laboratorija za primenu racunara u nauci,
Institut za fiziku Beograd,
Srbija.
URL: http://www.scl.rs/nenad

On 05/21/2013 02:22 PM, Nenad Vukmirovic wrote:
> Postovane koleginice i kolege,
>
> Pozivam vas na SCL seminar koji ce u petak 24. maja 2013. godine u 14:00
> u citaonici Instituta za fiziku odrzati Antun Balaz (SCL, Institut za
> fiziku u Beogradu). Naslov seminara i apstrakt su dati u nastavku ove
> poruke.
>
> Nonlinear Excitations in Bose-Einstein Condensates: Faraday Waves
>
> Abstract:
>
> In addition to collective oscillation modes, Bose-Einstein Condensates
> (BECs) exhibit a number of other excitations due to their inherent
> nonlinearity. Faraday (density) waves can be generated by a periodic
> modulation of the trapping potential or atomic interactions, and were
> first observed experimentally in 2007. Using the results of extensive
> numerical simulations and analytical variational calculations, we will
> show that elongated binary non-miscible BECs subject to periodic
> modulations of the radial confinement exhibit a Faraday instability
> similar to that seen in one-component condensates. Considering the
> hyperfine states of 87Rb condensates, we will show that there are two
> experimentally relevant stationary state configurations: the one in
> which the components form a dark-bright symbiotic pair (the ground state
> of the system), and the one in which the components are segregated
> (first excited state).
>
> For each of these two configurations, we will numerically demonstrate
> that far from resonances the Faraday waves excited in the two BEC
> components are of similar periods, emerge simultaneously, and do not
> impact the dynamics of the bulk of the condensate. We will also
> analytically derive the period of the Faraday waves using a variational
> treatment of the coupled Gross-Pitaevskii equations combined with a
> Mathieu-type analysis for the selection mechanism of the excited waves.
> Finally, we will show that for a modulation frequency close to twice
> that of the radial trapping, the emergent surface waves fade out in
> favor of a forceful collective mode that turns the two BEC components
> miscible.
>
> Srdacan pozdrav,
>