Numerical studies of a Matter-Wave Open Quantum System.*

In a recent experiment [1], we implement a model for an open quantum system consisting of an array of Weisskopf-Wigner type emitters (``artificial atoms'') realized with ultracold atoms in an optical lattice geometry [2]. Each emitter can spontaneously emit matter waves, with fully tunable decay strength and excited state energy. In a recent theoretical analysis [3], we studied a single site coupled to a one-dimensional waveguide and analyzed the transition from Markovian to non-Markovian dynamics including the formation of a bound state. In the experiment, we found strong qualitative deviations of the data compared to the single site analytical treatment. We present numerical studies on the effect of neighboring ground-state emitters, which suggest that the observed differences can be explained in terms of resonant re-absorption of emitted matter waves, such as tunneling and diffusion. We also propose schemes for direct characterization of transport properties in the lattice.
[1] L. Krinner et. al, in preparation.
[2] I. de Vega et. al, Phys. Rev. Lett. 101, 260404, 2008.
[3] M. Stewart et. al, Phys. Rev. A 95, 013626, 2017.