Large-scale Greenberger-Horne-Zeilinger states through a topologically protected zero-energy mode in a superconducting qutrit-resonator chain

We propose a superconducting qutrit-resonator chain model, and analytically work out forms of its topological edge states. The existence of the zero-energy mode enables one to generate a state transfer between two ends of the chain, accompanied with state flips of all intermediate qutrits, based on which N-body Greenberger-Horne-Zeilinger (GHZ) states can be generated with great robustness against disorders of coupling strengths. Three schemes of generating large-scale GHZ states are designed, each of which possesses the robustness against loss of qutrits or of resonators, meeting a certain performance requirement of different experimental devices. With experimentally feasible qutrit-resonator coupling strengths and available coherence times of qutrits and resonators, it has a potential to generate large-scale GHZ states among dozens of qutrits with a high fidelity. Further, we show the experimental consideration of generating GHZ states based on the circuit QED system, and discuss the prospect of realizing fast GHZ states.

Automated summary

A superconducting qutrit-resonator chain model is proposed, with analytically derived forms of its topological edge states and the generation of N-body GHZ states with robustness. Three schemes for generating large-scale GHZ states are designed, each with the ability to handle qutrit or resonator losses, showing potential for high fidelity among dozens of qutrits. Additionally, experimental considerations for generating GHZ states based on the circuit QED system and the prospect of fast GHZ state realization are discussed.