Distinguishment of Greenberger–Horne–Zeilinger States in Rydberg Atoms via Noncyclic Geometric Quantum Computation

Abstract

Since quantum entanglement plays a crucial role in quantum information processing, analyzing entangled states is indispensable for practical applications. Here a simple and direct protocol to distinguish arbitrary N‐qubit Greenberger–Horne–Zeilinger (GHZ) states by novel nonadiabatic noncyclic geometric quantum computation using Rydberg atoms is put forward. The Bell states can also be distinguished completely using this way. The protocol is justified by numerical simulation for Bell states and N‐qubit GHZ states, which evaluates the robustness and shows gratifying results. In addition, the idea is flexible, that is, available in any platform. Due to its simplicity and easy operation, the scheme would be very useful in quantum information science both theoretically and experimentally.

Quantum logic and entanglement by neutral Rydberg atoms: methods and fidelity

“…Notice that these approaches to Rydberg antiblockade can lead to many interesting schemes. For example, by using Rydberg antiblockade, reference [301] studied three-qubit gates and quantum error correction by a type of 'unconventional Rydberg pumping', references [302,303] studied a novel nondestructive parity meter in ground-state atoms, reference [304] studied a three-qubit controlled-phase gate with a tunable phase, references [305,306] showed methods to inter-convert the GHZ and W states, and reference [307] studied nonadiabatic noncyclic geometric phases in a Rydberg gate based on which reference [308] designed a scheme to distinguish different types of GHZ states with fidelities over 99.9% for GHZ states up to five qubits. Because the different interactions between different pairs of atoms in a multi-atom system can be different, by matching the detunings in the lasers with specific Rydberg interactions, interesting dynamics can be identified.…”