Single-photon scattering by two separated atoms in a supercavity

Wei Ming Zhu, Xiao Xiao, Duan-Lu Zhou +1 more

We study the single-photon scattering along a one-dimensional cavity array with two distant two-level atoms in a supercavity, which aims to simulate a recent x-ray experiment [ Nature 482 , 199 (2012)]. Without introducing dissipation, we find that when one atom is exactly located at a node of a mode of the supercavity and the other is at the antinode of that mode, no splitting of the reflectivity peak can appear. Nevertheless, the atom at the node significantly changes the positions of the reflectivity valleys. On the other hand, when the atom is shifted a little from the exact node, then the splitting can appear. We also explain these results with an analysis based on the general formal scattering theory. Our result implies the importance of non-resonant modes of the supercavity in our problem.

张者勇 ZHANG Zhe-yong, 董裕力 DONG Yu-li, 朱士群 ZHU Shi-qun

N. A. Enaki, Mihai Macovei

Lan Zhou, Hongxing Dong, Yu-xi Liu +2 more

We study single-photon transport in an array of coupled microcavities where two two-level atomic systems are embedded in two separate cavities of the array. We find that a single photon can be totally reflected by a single two-level system. However, two separate two-level systems can also create, between them, single-photon quasibound states. Therefore, a single two-level system in the cavity array can act as a mirror while a different type of cavity can be formed by using two two-level systems, acting as tunable ``mirrors,'' inside two separate cavities in the array. In analogy with superlattices in solid state physics, we call this ``cavity inside a coupled-cavity array'' a supercavity. This supercavity is the quantum analog of Fabry-Perot interferometers. Moreover, we show that the physical properties of this quantum supercavity can be adjusted by changing the frequencies of these two-level systems.

Lian Hai, Lei Tan, Jin-Shan Feng +3 more

Wei Ming Zhu, Zhihai Wang, Dong Zhou

We present a microscopic model of cavity quantum electrodynamics based on a one-dimensional (1D) coupled cavity array (CCA), where a supercavity (SC) is composed by a segment of the 1D CCA with relatively smaller couplings with the outsides. The single-photon scattering problem for the SC empty or with a two level atom in it is investigated. We obtain the exact theoretical result on the transmission rate for our system, which predicts that the transmission peaks shall appear near the eigenenergies of the SC. Our numerical results further prove that the SC is a well-defined multimode cavity. When a two level atom resonant with the SC locates at the antinode of the resonant mode, the transmission spectrum shows a clear sign of vacuum Rabi splitting as expected. However, when the atom locates at the node of the resonant mode, we observe a deep valley in the transmission peak, which can be explained by the destructive interference of two transmission channels: one is the resonant mode, while the other is arising from the atom coupling with the nonresonance modes. The effect of nonresonance modes on vacuum Rabi splitting is also analyzed.