Regulation of Entanglement and Geometric Quantum Discord of Hybrid Superconducting Qubits for Circuit

Yinghua Ji, Yongmei Liu

Yi Qian, Ye-Qi Zhang, Jing‐Bo Xu

Qian Qian, Yi Yi, Zhang +3 more

Yan‐Li Ji, Wenliang Li, S.J. Wen

Y. H. JI, Y. M. Liu

We investigate the dynamic evolution behaviors of entanglement and geometric quantum discord of coupled superconducting qubits in circuit QED system. We carefully analyze the effect of cavity field quantum state on the quantum entanglement and quantum correlations dynamic behaviors of coupling superconducting qubits. The results show that when the cavity field is in coherent state, with the average photon number increasing, the quantum discord death (including entanglement death) would become more difficult to appear, that is to say prolonging the survival time of quantum correlations will be a benefit for keeping the quantum correlations. When the cavity field is in squeezed state, the squeezed amplitude parameters are all too big or too small to keep the system quantum correlations. However, the further study results show that with the initial relative phase of coupling superconducting increasing, qubits can also keep the quantum correlations.

Juju Hu, Qiang Ke

We investigate the geometric quantum discord of coupling superconducting qubits in Fock state. In the non-Markovian noisy channel, the geometric quantum discord exhibits typical sudden change. The quantum correlation effect between qubits can be enhanced greatly and the initial disappearance time of entanglement can be delayed under certain circumstance through linearly modulating the coupling coefficient between qubits by a proper control function.