You are cordially invited to the SCL online seminar of the Center for the Study of Complex Systems, which will be held on Thursday, 11 Mary 2023 at 14:00 on Zoom. The talk entitled

Out of equilibrium dynamical properties of Bose-Einstein condensates in ramped up weak disorder

will be given by Dr. Milan Radonjić (SCL, Institute of Physics Belgrade; Institute of Theoretical Physics, University of Hamburg, Germany). The abstract of the talk:

In this talk we will discuss, from the theoretical point of view, how the superfluid and the condensate deformation of a weakly interacting ultracold Bose gas evolve during the ramping up of an external weak disorder potential. Both resulting deformations turn out to consist of two distinct contributions, i.e., a reversible equilibrium one [1,2], as well as a non-equilibrium dynamical one, whose magnitude depends on the details of the ramping protocol [3]. For the specific case of the exponential ramping up protocol, we will derive analytic time-dependent expressions for the aforementioned quantities. After sufficiently long time, the steady state emerges that is generically out of equilibrium. We will discuss how to examine properties of such a state by studying the relaxation dynamics into it. Also, we will consider the two-time correlation function and elucidate its relation to the equilibrium and the dynamical part of the condensate deformation.

[1] K. Huang and H.-F. Meng, Phys. Rev. Lett. 69, 644 (1992).
[2] B. Nagler, M. Radonjić et al., New J. Phys. 22, 033021 (2020).
[3] M. Radonjić and A. Pelster, SciPost Phys. 10, 008 (2021).

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