Dynamics of entanglement density in photonic crystals

Neda Foroozani, Mohammad Mehdi Golshan, Rosa Safaiee

Christoph Clausen, Imam Usmani, Félix Bussières +4 more

Xiaodong Liu, Shuguang Li, Xu Xing-Sheng +4 more

The dynamical characteristics of the spontaneous decay of a single excited atom or molecule depend strongly on its position within a photonic crystal (PC) and the relative orientation of its dipole and the electric field there. Measuring its dynamical characteristics of the spontaneous decay in a PC can only obtain the local density of states (DOS) in the PC, but cannot reflect the total DOS in the PC. It is found, theoretically, that using different number density distributions of luminescent molecules within the PC, one can probe the partial information or even all of the total DOS in the PC. In this paper, we separate, for the first time to our knowledge, the total DOS into two parts, DOS in the scatterer and DOS in the matrix of the Wigner-Seitz unit cell, according to their origin, and demonstrate that a special number density distribution of fluorescent molecules can reflect the total scatterers DOS or total matrix DOS or even both of them, i.e. the total DOS in the PC. This is meaningful in explaining and designing the experiments of prohibiting and enhancing the spontaneous emission of excited molecules.

Jie‐Hui Huang, Zhang-Yang Chen, Tianbao Yu +3 more

The time evolution of residual entanglement in a three-qubit system embedded in a photonic crystal is investigated by using a modified conjugate gradient method. In the isotropic photonic crystal the phenomena of entanglement ``sudden death'' and entanglement ``sudden birth'' are found due to the decoherence induced by the environment and its memory effect. Compared with the environment of an isotropic photonic crystal, entanglement has a longer lifetime in the anisotropic photonic crystal if the transition frequency is near the band edge. However, once the entanglement disappears, at a finite time in the anisotropic photonic crystal, it cannot revive, which means the phenomenon of entanglement sudden birth cannot happen in the anisotropic photonic crystal. The tripartite entanglement decays faster than bipartite entanglement in both types of photonic crystal, which indicates that multipartite entanglement is more fragile than bipartite entanglement in resisting quantum noise.

Jing Wang, Han Zhang, Yan Zhang +4 more

Yunan Wu, Jing Wang, Minglun Mo +1 more