Quantum state preparation and transfer based on the bound state in the doublon continuum
Phys. Rev. A 113, 053714 – Published 12 May, 2026
DOI: https://doi.org/10.1103/yhn3-vnyj
Abstract
Bound states in the continuum (BICs) have attracted intense interest, yet their many-particle counterparts remain largely unexplored in waveguide quantum electrodynamics. We identify and characterize a bound state embedded in the doublon continuum (BIDC) that emerges when four atoms couple to a coupled-resonator waveguide with strong on-site interaction. Exploiting this interaction-enabled BIDC, we show that (i) a distant, four-atom entangled state can be prepared with high fidelity, and (ii) quantum entangled states can be coherently transferred between spatially separated nodes. Our results establish a scalable mechanism for multiparticle state generation and routing in waveguide platforms, opening a route to interaction-protected quantum communication with many-particle BICs.
