Preparation of n-qubit Greenberger-Horne-Zeilinger entangled states in cavity QED: An approach with tolerance to nonidentical qubit-cavity coupling constants

TL;DR

This paper presents a method to generate n-qubit GHZ entangled states in cavity QED that is tolerant to nonuniform qubit-cavity couplings and does not require adjusting qubit levels during operation, enabling deterministic entanglement.

Contribution

It introduces a novel approach for GHZ state preparation that handles nonidentical qubit-cavity couplings without level adjustments, applicable to various physical systems.

Findings

Entanglement can be generated deterministically.

Operation time is independent of the number of qubits.

Method tolerates nonuniform qubit-cavity coupling constants.

Abstract

We propose a way for generating $n$-qubit Greenberger-Horne-Zeilinger (GHZ) entangled states with a three-level qubit system and (n-1) four-level qubit systems in a cavity. This proposal does not require identical qubit-cavity coupling constants, and thus is tolerant to qubit-system parameter nonuniformity and nonexact placement of qubits in a cavity. The proposal does not require adjustment of the qubit-system level spacings during the entire operation. Moreover, it is shown that entanglement can be deterministically generated using this method and the operation time is independent of the number of qubits. The present proposal is quite general, which can be applied to physical systems such as various types of superconducting devices coupled to a resonator or atoms trapped in a cavity.