What it is
Researchers generated Gottesman-Kitaev-Preskill (GKP) qubit states on an ultra-low-loss integrated photonic chip built on a 300-millimetre silicon-nitride wafer and coupled to photon-number-resolving detectors. The states show the structure fault tolerance needs: at least four resolvable peaks in both quadratures and a 3 by 3 grid of negative Wigner-function regions, moving GKP generation off bulky free-space optics and onto a scalable chip.
Why it matters
GKP states enable universal gates with simple room-temperature operations but have been made only with free-space optics that cannot scale. Producing them on-chip is a prerequisite for arrays that feed a real machine.
Underlined numbers link to their source. Every metric and quoted figure is listed under Sources and data below.
Filed underphotonic quantum computing, GKP states, integrated photonics, fault tolerance, bosonic codes