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

摘要

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 qubitsystems in a cavity. This proposal does not require identical qubit-cavitycoupling constants, and thus is tolerant to qubit-system parameternonuniformity and nonexact placement of qubits in a cavity. The proposal doesnot require adjustment of the qubit-system level spacings during the entireoperation. Moreover, it is shown that entanglement can be deterministicallygenerated using this method and the operation time is independent of the numberof qubits. The present proposal is quite general, which can be applied tophysical systems such as various types of superconducting devices coupled to aresonator or atoms trapped in a cavity.