Dynamic control of the photonic band gap using quantum coherence (5 pages)

Li -, Sadeghi, Huang

Concita Sibilia, Jan Peřina

M. A. Antón, F. Carreño

Xue Mei Su, Byoung Seung HAM

We propose a scheme of employing quantum interference and coherence in an optical medium with coupled electromagnetic fields to create a photonic band gap. A variable photonic band gap is achieved by the cross-phase-modulation of two counterpropagating coupling fields on a weak probe pulse. The proposed photonic band gap has potential applications for the dynamic control of group velocity dispersion compensation in fiber-optic communications.

Ghafar Ahmadi, Shahpoor Saeidian, Ghasem Naeimi

The time evolution of quantum Fisher information, quantum coherence, and non-Markovianity of a V-type three-level atom embedded in free space or a photonic band gap crystal have been investigated. It has been demonstrated that the photonic band gap crystal, as a structured environment, significantly influences the preservation and enhancement of these quantum features. Additionally, we observe that by manipulating the initial relative phase values encoded in the atomic state and the relative positions of the upper levels within the forbidden gap, control over the dynamics of quantum features can be achieved. These findings highlight the potential benefits of utilizing photonic band gap crystals in quantum systems, offering improved preservation and manipulation of quantum information. The ability to control quantum features opens new avenues for applications in quantum information processing and related technologies.

Jin-Wei Gao, Qian-Qian Bao, Ren-Gang Wan +2 more

We study a cold atomic sample coherently driven into the five-level triple-$\ensuremath{\Lambda}$ configuration for attaining a dynamically controlled triple photonic band-gap structure. Our numerical calculations show that three photonic band gaps with homogeneous reflectivities up to $92%$ can be induced on demand around the probe resonance by a standing-wave driving field in the presence of spontaneously generated coherence. All these photonic band gaps are severely malformed with probe reflectivities declining rapidly to very low values when spontaneously generated coherence is gradually weakened. The triple photonic band-gap structure can also be attained in a five-level chain-$\ensuremath{\Lambda}$ system of cold atoms in the absence of spontaneously generated coherence, which however requires two additional traveling-wave fields to couple relevant levels.