Topological states in a Rydberg composite

Peter Schmelcher, Michael Mayle, Igor Lesanovsky

S. K. Kanungo, J. D. Whalen, Yi Lu +5 more

Matthew T. Eiles, Christopher W. Wächtler, Alexander Eisfeld +1 more

We examine topological phases and symmetry-protected electronic edge states in the context of a Rydberg composite: a Rydberg atom interfaced with a structured arrangement of ground-state atoms. We show that the spectrum of the electronic Hamiltonian of such a composite possesses a mapping to that of a tight-binding Hamiltonian, which can exhibit nontrivial topology depending on the arrangement of the ground-state atoms and the principal quantum number of the Rydberg state. The Rydberg electron moves in a combined potential including the long-ranged Coulomb interaction with the Rydberg core and short-ranged interactions with each neutral atom; the effective hopping amplitudes between sites are determined by this combination. We first confirm the existence of topologically-protected edge states in a Rydberg composite by mapping it to the paradigmatic Su-Schrieffer-Heeger dimer model. Following that, we show that more complicated systems with trimer unit cells can be studied in a Rydberg composite. Published by the American Physical Society 2024

Antoine Browaeys

Lei Pan, Hui Zhai

The Rydberg blockade induces strongly correlated many-body effects in Rydberg atom arrays, including rich ground-state phases and many-body scar states in the excitation spectrum.In this Letter, we propose a composite spin representation that can provide a unified description for major features in this system.The composite spin combines Rydberg excitation and the auxiliary fermions, which are introduced to implement the Rydberg blockade constraint automatically.First, we focus on the PXP model describing one-dimensional arrays with the Rydberg blocking radius being a lattice spacing.Using composite spins, the ground state is simply a polarized product state of composite spins, and the magnon excitations of these composite spins can accurately describe the many-body scar states and signal the quantum phase transition driven by detuning.Then, we show that Rydberg atom arrays with different blocking radii can share a universal description in terms of the composite spin representation, and the difference between different blockade radii can be absorbed in the formation of composite spins.Hence, our scheme provides a universal physical picture of the blockade effect in Rydberg atom arrays.

Thierry Lahaye