Nonlinear Dynamics in Quantum Photonic Structures

Xin Wang, Jiaqi Li, Tao Liu +2 more

Multiphoton dynamics beyond linear optical materials are of significant fundamental and technological importance in quantum information processing. However, it remains largely unexplored in nonlinear waveguide QED. In this work, we theoretically propose a structured nonlinear waveguide in the presence of staggered photon-photon interactions, which supports two branches of gaped bands for doublons (i.e., spatially bound-photon-pair states). In contrast to linear waveguide QED systems, we identify two important contributions to its dynamical evolution, i.e., single-photon bound states (SPBSs) and doublon bound states (DBSs). Most remarkably, the nonlinear waveguide can mediate the long-range four-body interactions between two emitter pairs, even in the presence of disturbance from SPBSs. By appropriately designing system's parameters, we can achieve high-fidelity four-body Rabi oscillations mediated only by virtual doublons in DBSs. Our findings pave the way for applying structured nonlinear waveguide QED in multi-body quantum information processing and quantum simulations among remote sites. Published by the American Physical Society 2024

Guanglei Wang

Alex S. Clark, L. G. Helt, Matthew J. Collins +4 more

Chaohan Cui, Liang Zhang, Linran Fan

We report the in situ control of integrated Kerr nonlinearity through its interplay with the cascaded Pockels nonlinear process. Effective Kerr nonlinearity is tuned over 10 dB dynamic range at single photon level without modifying photonic structures.

Daniel F. Walls, Gerard J Milburn

Chaohan Cui, Liang Zhang, Linran Fan

Kerr nonlinearity in nanophotonic cavities provides a versatile platform to explore fundamental physical sciences and develop novel photonic technologies. This is driven by the precise dispersion control and significant field enhancement with nanoscale structures. Beyond dispersion and pump engineering, the direct control of Kerr nonlinearity can release the ultimate performance and functionality of photonic systems. Here, we report the in situ control of integrated Kerr nonlinearity through its interplay with the cascaded Pockels nonlinear process. Kerr nonlinearity is tuned over 10~dB dynamic range without modifying photonic structures. Fano resonance is observed with nonlinear spectrum, in contrast to standard linear transmission. This confirms the quantum interference between competing optical nonlinear pathways. Besides nonlinearity enhancement, we also demonstrate the novel capability to suppress the material intrinsic nonlinearity. Finally, we use the tunable nonlinearity to control the spectral brightness and coincidence-to-accidental ratio of single-photon generation. This work paves the way towards the complete nanoscale control of optical nonlinear processes at quantum level.