Topologically protected synthesizing of Fock states in a circuit QED architecture

The preparation of Fock states is important for quantum information storage and processing. Here we present a two‐step protocol with topological protection for multi‐photon Fock states synthesizing in a circuit QED architecture. Due to photon number‐dependent vacuum Rabi splitting, the dynamics of the Jaynes‐Cummings ladder in the resonant regime can be equivalent to a spin‐1/2 chain while a multi‐frequency microwave pulse is applied. Based on the topologically assisted quantum state transfer technique, multi‐photon Fock states can be conditionally generated. Our method significantly reduces the complexity of experimental manipulation compared with previous multi‐step methods and is more robust as a result of topological protection. Furthermore, the protocol indicates that the circuit QED architecture could potentially provide a platform to explore the exotic phase in condensed matter.This article is protected by copyright. All rights reserved.