Efficient generation of Greenberger–Horne–Zeilinger states of N driven qubits mediated by a cavity.

In this paper, we propose a protocol for generating N-qubit Greenberger–Horne–Zeilinger (GHZ) states in a superconducting system. The physical model contains N superconducting flux qubits and a cavity, where the N superconducting flux qubits are coupled to the cavity simultaneously. The preparation of GHZ states can be realized in one step by applying a pair of classical fields to each qubit. The protocol is promising for generating N-qubit GHZ states because the operation time is independent of the number of the qubits in the strong drive regime. Furthermore, we consider the effects of random noise and decoherence, and numerical simulations show that the protocol is insensitive to these disturbing factors. Therefore, the protocol may be useful in the generation of GHZ states. [ABSTRACT FROM AUTHOR]