[institut] Reminder: SCL Seminar Today: Antun Balaž

[Nenad Vukmirovic]

Dear colleagues,

You are cordially invited to the SCL seminar of the Center for the Study 
of Complex Systems, which will be held on Friday, 18 November 2016 at 
14:00 in the library reading room “Dr. Dragan Popović" of the Institute 
of Physics Belgrade. The talk entitled

Dirty bosons in a quasi-one-dimensional harmonic trap

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

We will consider the emergence of a Bose-glass region in a quasi 
one-dimensional Bose-Einstein-condensed gas in a harmonic trapping 
potential with an additional delta-correlated disorder potential at zero 
temperature using three approaches [1]. At first, we will solve the 
corresponding time-independent Gross-Pitaevskii equation numerically for 
the condensate wave function, and evaluate disorder ensemble averages. 
In particular, we will analyze quantitatively the emergence of 
mini-condensates in the local minima of the random potential, which 
occurs for weak disorder preferentially at the border of the condensate, 
while for intermediate disorder strength this happens in the trap 
centre. Second, in view of a more detailed physical understanding of 
this phenomenon, we will extend a recent non-perturbative approach 
towards the weakly interacting dirty boson problem, which relies on the 
Hartree-Fock theory and is worked out on the basis of the replica 
method, from the homogeneous case to a harmonic confinement. Finally, in 
the weak disorder regime we also apply the Thomas-Fermi approximation, 
while in the intermediate disorder regime we additionally use a 
variational ansatz in order to describe analytically the numerically 
observed redistribution of the fragmented mini-condensates with 
increasing disorder strength.

[1] T. Khellil, A. Balaž, and A. Pelster, New J. Phys. 18, 063003 (2016).

Best regards,

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