Eur. Phys. J. D (2012) 66: 133
https://doi.org/10.1140/epjd/e2012-20688-1

Regular Article

Quantum discord evolution of three-qubit states under noisy channels

¹ Department of Theoretical Physics and Astrophysics, University of Tabriz, 51664 Tabriz, Iran
² Department of Physics, University of Kurdistan, P.O. Box 66177-15175, Sanandaj, Iran

^a e-mail: mahdian@tabrizu.ac.ir

Received: 29 November 2011
Received in final form: 29 January 2012
Published online: 23 May 2012

Abstract

We investigated the dissipative dynamics of quantum discord for correlated qubits under Markovian environments. The basic idea in the present scheme is that quantum discord is more general, and possibly more robust and fundamental, than entanglement. We provide three initially correlated qubits in pure Greenberger-Horne-Zeilinger (GHZ) or W state and analyse the time evolution of the quantum discord under various dissipative channels such as: Pauli channels σ_x, σ_y, and σ_z, as well as depolarising channels. Surprisingly, we find that under the action of Pauli channel σ_x, the quantum discord of GHZ state is not affected by decoherence. For the remaining dissipative channels, the W state is more robust than the GHZ state against decoherence. Moreover, we compare the dynamics of entanglement with that of the quantum discord under the conditions in which disentanglement occurs and show that quantum discord is more robust than entanglement except for phase flip coupling of the three-qubits system to the environment.