Realizing topological edge states with Rydberg-atom synthetic dimensions

Area of Science:

• Quantum Simulation
• Topological Matter
• Atomic Physics

Background:

• Synthetic dimensions offer enhanced control for quantum simulations, enabling access to complex configurations.
• Real-space lattice potentials are foundational, but synthetic dimensions provide novel avenues for exploration.
• The Su-Schrieffer-Heeger (SSH) Hamiltonian is a key model for understanding topological phases of matter.

Purpose of the Study:

• To demonstrate a synthetic-dimension approach for realizing the SSH Hamiltonian using ultracold atoms.
• To engineer tunable tunneling amplitudes and on-site potentials via millimeter waves.
• To investigate the emergence of topological edge states in this synthetic lattice.

Main Methods:

• Utilized ultracold 84Sr atoms in a synthetic dimension based on Rydberg levels coupled by millimeter waves.
• Controlled tunneling amplitudes and on-site potentials using millimeter-wave amplitudes and detunings.
• Probed band structure and identified edge states via optical excitation and analysis of Rydberg levels.

Main Results:

• Successfully realized the single-particle SSH Hamiltonian in a one-dimensional synthetic lattice.
• Observed symmetry-protected topological edge states at zero energy within the band structure.
• Demonstrated robustness of edge-state energies to perturbations preserving chiral symmetry.

Conclusions:

• Synthetic dimensions provide a powerful platform for simulating topological matter, exemplified by the SSH model.
• The engineered Rydberg-level system allows for precise control over topological properties.
• Edge-state properties are sensitive to symmetry-breaking perturbations, offering further avenues for control.