Robust qubit interactions mediated by photonic topological edge states

TL;DR

This paper explores how topologically protected edge states in a 2D lattice can mediate long-range, coherent interactions between spatially separated qubits, with potential applications in quantum information transport.

Contribution

It provides an analytical framework for understanding qubit interactions via topological edge modes beyond perturbative approximations.

Findings

Effective qubit coupling depends on placement, detuning, and topological properties.

Analytical solutions reveal full interplay between qubits and edge states.

Conditions for coherent interactions are identified.

Abstract

We investigate the coupling of two spatially separated qubits via topologically protected edge states in a two-dimensional Hofstadter lattice. In this hybrid platform, the qubits are coupled to distinct edge sites of the lattice, enabling long-range interactions mediated by topological edge modes. We solve the full system Hamiltonian and analyze the resulting eigenstate structure to uncover the conditions under which coherent qubit interactions emerge. Our analysis reveals that the effective coupling is highly sensitive to the qubit placement, energy detuning, and the topological character of the edge spectrum. We obtain an analytical solution that goes beyond the perturbative regime, capturing the full interplay between the qubits and edge modes. These results provide a foundation for exploring information transport and many-body effects in engineered quantum systems where interactions are mediated by topological edge modes.