Nature CommunicationsNon-reciprocal frequency conversion in a non-Hermitian multimode nonlinear systemSahil PontulaSachin VaidyaCharles Roques-CarmesShiekh Zia UddinMarin SoljačićYannick Salamin2025-08-14Full textDOI https://doi.org/10.1038/s41467-025-62853-0