[institut] Reminder: SCL Seminar Today: Antun Balaž

[Nenad Vukmirovic]

Dear colleagues,

You are cordially invited to the SCL seminar which will be held on 
Friday, 28 October 2016 at 14:00 in “Dr. Dragan Popović” library reading 
room of the Institute of Physics Belgrade. The talk entitled

Order and chaos in BEC dynamics

will be given by Dr Antun Balaž (Scientific Computing Laboratory, 
Institute of Physics Belgrade). Abstract of the talk:

We will discuss conditions for order and chaos in the dynamics of an 
interacting Bose-Einstein condensate (BEC) confined by an external trap 
cut off by a hard-wall box potential [1]. The BEC is stirred by a laser 
to induce excitations manifesting as irregular spatial and energy 
oscillations of the trapped cloud. Adding laser stirring to the external 
trap results in an effective time-varying trapping frequency in 
connection with the dynamically changing external plus laser potential 
trap. The resulting dynamics will be analyzed numerically [2-5] by 
plotting the corresponding trajectories in coordinate, phase, and energy 
space. We also compute the Lyapunov exponents to confirm the existence 
of chaos in energy space. We will identify quantum effects and trap 
anharmonicity as main culprits for emergence of chaos in the system. 
However, the presence of chaos in energy space does not necessarily 
translate into chaos in coordinate space. In general, time-varying 
trapping frequency is found to promote chaos in a trapped BEC. On the 
other hand, we find that a suppression of chaos in a trapped BEC can be 
achieved by increasing the characteristic scale of the external trap 
with respect to the condensate size.

[1] R. R. Sakhel, et. al., Eur. Phys. J. D 70, 66 (2016).
[2] D. Vudragović, et. al., Comput. Phys. Commun. 183, 2021 (2012).
[3] V. Lončar, et. al., Comput. Phys. Commun. 200, 406 (2016).
[4] B. Satarić, et. al., Comput. Phys. Commun. 200, 411 (2016).
[5] V. Lončar, et. al., Comput. Phys. Commun. 209, 190 (2016).

Best regards,

-- 
Dr Nenad Vukmirović,
Research Professor,
Scientific Computing Laboratory,
Institute of Physics Belgrade,
Serbia.
URL: http://www.scl.rs/nenad