Physics

Dr. Bodhaditya Santra
University of Hamburg, Germany

Understanding the non-equilibrium dynamics of an interacting system lies at the heart of many-body physics. How a closed system transits from an initial out-of-equilibrium state to a final equilibrium state is not yet clearly understood. The ability to design, control and probe such states pave the way towards understanding local and global properties of non-equilibrium dynamics. Ultracold quantum gases offers unique possibilities to study such non-equilibrium quantum dynamics in a highly controllable and precisely tunable setup. In the first part of my talk I will present the results obtained with an 87Rb Bose-Einstein condensate (BEC) loaded in an optical lattice. Using a scanning electron microscope (SEM) [1], we prepared the initial state and observed “Negative differential conductivity” in an interacting quantum gas [2]. By using the SEM as a dissipative potential on a single lattice site we observed bistability in a driven dissipative superfluid [3]. We also measured the build-up of phase coherence after a quantum quench of a BEC residing in a one-dimensional optical lattice using Talbot interferometry [4]. In the last part of my talk I will present the recent progress of a 173Yb Fermi gas experiment towards quantum simulation of lattice systems with orbital degrees of freedom, like Kondo lattice model. [1] B. Santra and H. Ott, J. Phys. B. 48, 122001 (2015) [2] R. Labouvie, B. Santra, S. Heun, S. Wimberger, H. Ott, Phys. Rev. Lett. 115, 050601 (2015) [3] R. Labouvie, B. Santra, S. Heun, H. Ott, Phys. Rev. Lett. 116, 235302 (2016) [3] B. Santra, C. Baals, R. Labouvie, A. Bhattacherjee, A. Pelster, H. Ott, Nat. Commun. 8, 15601 (2017)