Doublons, topology and interactions in a one-dimensional lattice

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics
• Topological Materials

Background:

• The Su-Schrieffer-Heeger model describes topological properties in one-dimensional systems.
• Coupled oscillators with on-site interactions form the basis of the Bose-Hubbard model.
• Dimerization introduces significant variations in lattice properties.

Purpose of the Study:

• Investigate the Bose-Hubbard model applied to a dimerized topological chain.
• Characterize emergent quantum states in the two-excitation subspace.
• Explore the interplay of dimerization, topology, and interactions.

Main Methods:

• Theoretical investigation of the Bose-Hubbard model.
• Analysis of one-dimensional dimerized chains.
• Focus on the two-excitation subspace.

Main Results:

• Identification of scattering bands with extended states.
• Observation of bound bands featuring two-particle pairs (doublons).
• Characterization of various topological edge states.

Conclusions:

• The competition between couplings, topology, and interactions dictates emergent states.
• Demonstrated phenomena are realizable in photonic cavities, optical lattices, and qubits.
• Provides a foundation for topological two-particle and many-body physics.