Eur. Phys. J. B 83, 465-474 (2011)
https://doi.org/10.1140/epjb/e2011-20072-7

Regular Article

Controllable coupling and quantum correlation dynamics of two double quantum dots coupled via a transmission line resonator

¹ Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, and Department of Physics, Hunan Normal University, Changsha 410081, P.R. China
² Department of Physics and electronics, Hunan Institute of Science and Technology, Yueyang 414000, P.R. China

^a Corresponding author: lmkuang@hunnu.edu.cn

Received: 27 January 2011
Received in final form: 17 July 2011
Published online: 17 October 2011

Abstract

We propose a theoretical scheme to generate a controllable and switchable coupling between two double-quantum-dot (DQD) spin qubits by using a transmission line resonator (TLR) as a bus system. We study dynamical behaviors of quantum correlations described by entanglement correlation (EC) and discord correlation (DC) between two DQD spin qubits when the two spin qubits and the TLR are initially prepared in X-type quantum states and a coherent state, respectively. We demonstrate that in the EC death regions there exist DC stationary states in which the stable DC amplification or degradation can be generated during the dynamical evolution. It is shown that these DC stationary states can be controlled by initial-state parameters, the coupling, and detuning between qubits and the TLR. We reveal the full synchronization and anti-synchronization phenomena in the EC and DC time evolution, and show that the EC and DC synchronization and anti-synchronization depends on the initial-state parameters of the two DQD spin qubits. It is shown that the initial quantum correlation may be suppressed completely when the evolution time approaches to the infinity in the presence of dissipation. These results shed new light on dynamics of quantum correlations.