NCTS (South)


DATE2012-06-04

TIME12:00

PLACER49223, Second Physics Building , NCKU

FIELDQuantum Information Science

SPEAKER Dr. Jing-Nuo Wu(吳靜娜) - 文化大學物理系

TITLEEffect of photonic band gap on entanglement dynamics of qubits in anisotropic photonic crystals

ABSTRACT We study how the environment of anisotropic band gap (PBG) materials affects entanglement dynamics of qubits. Entanglement between the single qubit and the PBG environment is investi-gated through the von Neumann entropy while that for two initially entangled qubits in this PBG reservoir is through concurrence. Dynamics of these measurenments are solved through fractional calculus which has been shown appropriate for the system with non-Markovian dynamics. Entropy dynamics of the single qubit system reveals that the eff ect of PBG reservoir prevents decoherence of the qubit through the steady entropy with non-zero value. The eff ect of PBG reservoir on the concurrence of the two-qubit system leads to the long-time entanglement preservation. The concurrence dynamics of the two qubits shows that unphysical entanglement trapping does not exist in the system with the qubit frequency lying outside the PBG region.
Long-time memory eff ect of the PBG reservoir occurs only for the qubit frequency in the PBG region. We propose to transfer the experience of the photonic crystals about the controllable long-time memory e ffect to the superconducting system of transmon qubits in the middle of tunable arti cial crystals through this study.