Multipartite Entanglement in a Microwave Frequency Comb
Shan W. Jolin, Gustav Andersson, J. C. Rivera Hernández, Ingrid Strandberg, Fernando Quijandría, José Aumentado, Riccardo Borgani, Mats O. Tholén, David B. Haviland
Abstract
Significant progress has been made with multipartite entanglement of discrete qubits, but continuous variable systems may provide a more scalable path toward entanglement of large ensembles. We demonstrate multipartite entanglement in a microwave frequency comb generated by a Josephson parametric amplifier subject to a bichromatic pump. We find 64 correlated modes in the transmission line using a multifrequency digital signal processing platform. Full inseparability is verified in a subset of seven modes. Our method can be expanded to generate even more entangled modes in the near future.