Strong coupling between a single-photon and a two-photon Fock state.

ABSTRACT: The realization of strong nonlinear coupling between single photons has been a long-standing goal in quantum optics and quantum information science, promising wide impact applications, such as all-optical deterministic quantum logic and single-photon frequency conversion. Here, we report an experimental observation of the strong coupling between a single-photon and a two-photon Fock state in an ultrastrongly-coupled circuit-QED system. This strong nonlinear interaction is realized by introducing a detuned flux qubit working as an effective coupler between two modes of a superconducting coplanar waveguide resonator. The ultrastrong light-matter interaction breaks the excitation number conservation, and an external flux bias breaks the parity conservation. The combined effect of the two enab

SUBMITTER: Wang SP 

PROVIDER: S-EPMC12484861 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature