DInTopF · Disorder and Interactions in Topological Floquet Systems
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-04-01 → 2023-03-31
- EU contribution
- €162,806
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Disorder and Interactions in Topological Floquet Systems
The DInTopF project aimed at experimentally exploring the topological properties of Floquet systems with ultracold atoms in modulated hexagonal optical lattices. The project was based on an existing experimental setup where the topology of the bulk of such a system had already been studied. The objectives of the project were the following: 1. Improve the experimental setup to be able to directly observe edge states in these systems and gain an innovative tool to characterize the topology of a system. 2. Improving how the optical lattice is generated and controlled in order to add a sublattice energy in the hexagonal lattice and be able to probe new regions of the phase diagram, including a phase with Chern number 2. 3. Adding tools to the experiment to generate disorder in the energy landscape of the optical lattice, and study the interplay between topology and disorder. There are two specific questions that had been anticipated: (a) How can the addition of disorder change the topology of a band; (b) How can an anomalous phase have localized states in the bulk and chiral edge states on the border of the material (WP2) 4. Add a stronger vertical confinement to the atoms in order to increase the interactions between particles and, in combination to the natural Feshbach resonance of the potassium atoms that are used, bring the system to a strongly interacting regime. The goals there are two-fold: (a) Investigate whether there is a phase where disorder brings the bulk of the system in a many-body-Anderson-localized state, and at the same time where chiral edge states still sustain transport on the border of the material. (b) Without disorder, the statistics of strongly interacting bosons in the Floquet system can be transformed into one similar to a fermionic statistics.
Data: CORDIS, © European Union
Project objective
This project aims at studying the topological properties of ultracold atoms in a periodically-driven honeycomb optical lattice in the presence of disorder and interactions. It relies on an already-existing experimental setup that can routinely create topological Floquet phases with weakly-interacting bosonic potassium atoms. The development of several technical tools will allow for the investigation of yet-unexplored topological phases of matter and bring solutions to the inherent heating due to the periodic driving.A first task is the direct observation of topological edge states and the realization of a Chern number 2 topological phase. This requires the implementation of a box potential and a better control of the laser beams providing the optical lattice. It will provide for the first time a complete picture of the bulk-edge correspondence and of the phase diagram of Floquet systems.A second set of experiments involves the setting of a disorder potential, and will bring into light the interplay between topology and disorder in periodically-driven systems. In particular the existence of disorder-induced topological phases such as the anomalous Floquet Anderson insulator will be demonstrated. In this phase, the bulk is fully localized and topologically-protected edge states do exist.In the last part of the project, a vertical confinement will be implemented, and it will be combined with the tuning of interactions with a Feshbach resonance to bring the system to a strongly-interacting regime. There, interesting phases of matter can be explored, such as a fermionization of the gas loaded in a so-called moat band. More strikingly, a topological many-body-localized Floquet phase can be realized, where the strongly-interacting particles undergo a periodic driving, but are resilient to heating while supporting a topological edge state.
Original text from CORDIS.
Participants
- LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN · PlaneggCoordinatorGermany
Links
Data: CORDIS, © European Union