LPTMS Internship Proposal: Searching for topological physics in dissipative Ytterbium gases

Dissipation is ubiquitous in experiments on quantum matter and it typically reduces the timescales
over which pristine quantum phenomena can be investigated or lowers the quality of the
measurements. It’s an “enemy” that has to be fought harshly and roughly. In this internship we
will change the paradigm and consider dissipation as a resource. Dissipation can induce genuine
and interesting quantum effects (see for instance Ref. 1) and we are interesting in proposing
realistic experiments that can reveal them.

We will focus on the experiments on ultracold ytterbium gases that are currently realized in
several laboratories around the world, among which those at Collège de France in Paris (see
Ref. 2). The goal of this internship is to characterize theoretically the interplay between (i) the
dissipative mechanisms that distinguish these atoms and (ii) the unavoidable presence of atomatom
interactions (Ref. 3 presents some first data obtained in Hamburg, Germany). We will
inspect whether the dissipation-induced topological properties presented in the model of
reference 4, where interactions are neglected, can be observed in Ytterbium gases, where
interactions cannot be neglected. The main investigation tool will be advanced numerical
algorithms based on matrix-product states, that allow for the study of dissipative many-body
systems (see Ref. 5 for an article where such methods have been used to characterize dissipative
topological models).

1. F. Verstraete, M. W. Wolf and J. I. Cirac, Nature Physics 5, 633 (2009).
2. R Bouganne et al., New J. Phys. 19, 113006 (2017).
3. K. Sponselee et al., arXiv:1805.11853 (2018).
4. M. S. Rudner and L. S. Levitov, Phys. Rev. Lett. 102, 065703 (2009).
5. F. Iemini, D. Rossini, R. Fazio, S. Diehl and L. Mazza, Phys. Rev. B 93, 115113 (2016)

Leonardo MAZZA