Controllable quantum interference and photon transport in a three-mode closed-loop cavity-atom system

In recent years, it is a hot topic to study the interaction between atomic ensemble and cavities, and many researches have been done in this regard. In such systems, some atoms are trapped in the cavity, to study their dynamic characteristics, e.g., the evolution of photon numbers and photon transition. The Jaynes-Cummings model is an important basic model for studying the dynamic characteristics of the cavity-atom system, which is based on the interaction between a single two-level atom and the cavity field. Recently, coherent photon control in cavities under specific conditions has become an important part of quantum computing and communication. It is worth noting that the tunable photon transmission and all-optical switches based on the cavity have already aroused superhigh interest and have been applied in many prospects. The quantum information and networks are mostly rooted in complex optical devices, which may show nonreciprocal or asymmetric photon transport. In this paper, we demonstrate that by using an optical closed-loop system the unconventional photon transport can be realized with two mutually perpendicular cavities coupled through external fiber and the two-level atom placed on the intersection. This three-mode system supports two orthogonal propagation directions, that is to say, and interaction among

Controllable quantum interference and photon transport in a three-mode closed-loop cavity-atom system Yu-Fei Dai 1) Yao-Tong Chen 1) Lan Wang 1) Kai Yin 2) Yan Zhang In recent years, it is a hot topic to study the interaction between atomic ensemble and cavities, and many researches have been done in this regard.
In such systems, some atoms are trapped in the cavity, to study their dynamic characteristics, e.g., the evolution of photon numbers and photon transition.The Jaynes-Cummings model is an important basic model for studying the dynamic characteristics of the cavity-atom system, which is based on the interaction between a single two-level atom and the cavity field.Recently, coherent photon control in cavities under specific conditions has become an important part of quantum computing and communication.It is worth noting that the tunable photon transmission and all-optical switches based on the cavity have already aroused superhigh interest and have been applied in many prospects.The quantum information and networks are mostly rooted in complex optical devices, which may show nonreciprocal or asymmetric photon transport.In this paper, we demonstrate that by using an optical closed-loop system the unconventional photon transport can be realized with two mutually perpendicular cavities coupled through external fiber and the two-level atom placed on the intersection.This three-mode system supports two orthogonal propagation directions, that is to say, and interaction among 最 新 录 用 probe fields are mutually perpendicular.Without ignoring the spontaneous decay of the natural atom, the complex and controllable quantum interference induced by the efficient hybrid interaction of the light, cavity modes, and the atom in such a closed-loop structure can result in a few interesting symmetric and asymmetric photon transport behaviors, i.e., coherent perfect synthesis and coherent perfect reflection.Aside from these compelling properties, the group velocity also can be modulated, i.e., fast and slow light effect.All of these processes can be dynamically controlled in terms of the probe field phase difference, the tunneling coupling between two cavities and the coupling between the cavity and the atom.Of importance, as so many advantages, such a tunable scheme can be readily extended to some optical devices, e.g., the switch and the router that is challenging to conventional optical devices.

Fig. 1 .
Fig.1.(Color online) (a) Schematic diagram of an optical system composed of two optical cavities and the atomic ensemble.(b) Realistic setup of that optical system with the double-cavity orthogonal structure.

Fig. 3 .
Fig.3.Normalized output field intensities a I (red-line) and b I (blue-line) vs. the relative phase 

Keywords:
Cavity-atom system • Quantum interference • Controllable photon transport * Project supported by the National Natural Science Foundation of China (Grant No. 11704064), the Scientific and Technological Development Program of Jilin Province, China (Grant No. 20180520205JH), and the Science Foundation of the Education Department of Jilin Province During the 13th Five-Year Plan Period, China (Grant No. JJKH20180010KJ), and the Fundamental Research Funds for the Central Universities, China (2412019FZ045).