Shields up!: Specialized conductive materials are used to shield or block electromagnetic radiation such as microwaves or radio waves to either prevent the escape of stray radiation or prevent interference from unwanted sources. Ideal materials should show high effective shielding while requiring a small volume or mass of material. Materials from the MXene family of two-dimensional ceramics, where M is a transition metal and X is either carbon or nitrogen, have shown excellent shielding properties. Iqbal et al. now show even better and somewhat unexpected performance from a metal carbon nitride. Science , this issue p. 446

Silicon is the ideal material for building electronic and photonic circuits at scale. Integrated photonic quantum technologies in silicon offer a promising path to scaling by leveraging advanced semiconductor manufacturing and integration capabilities. However, the lack of deterministic quantum light sources and strong photon-photon interactions in silicon poses a challenge to scalability. In this work, we demonstrate an indistinguishable photon source in silicon photonics based on an artificial atom. We show that a G center in a silicon waveguide can generate high-purity telecom-band single photons. We perform high-resolution spectroscopy and time-delayed two-photon interference to demonstrate the indistinguishability of single photons emitted from a G center in a silicon waveguide. Our results show that artificial atoms in silicon photonics can source single photons suitable for photonic quantum networks and processors.