He Guangqiang and Jiang Chun of Shanghai Jiaotong University have made scientific progress in the field of topological quantum optics
He Guangqiang and Jiang Chun of Shanghai Jiaotong University have made scientific progress in the field of topological quantum optics
Recently, He Guangqiang's team and Jiang Chun's team of State Key Laboratory of Regional Optical Fiber Communication Networks and New Optical Communication Systems, Department of Electronic Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University have made progress in the field of topological quantum optics. The research results are called Topological protection of continuous frequency entangled Biphoton states (Topologically protected continuous frequency entangled two-photon states) was published in the international journal Nanophotonics. This work presents a scheme to achieve topologically protected continuous-frequency entangled two-photon states in optical topological insulators.
Research Background
Quantum entanglement describes the interrelated properties between two or more physical subsystems, and is currently widely used in the fields of quantum communication, quantum computing and quantum precision measurement. However, the signal strength of the entangled state is often weak, and it is vulnerable to external interference, and the signal is easily distorted in the more complex path transmission.
Innovative achievements
In response to these problems, the research team proposed a topologically protected continuous frequency entangled two-photon state theoretical scheme, as shown in the figure below. Based on the quantum valley Hall effect, an optical topological insulator can be constructed in a photonic crystal, and topology appears in the topological band gap. The topological boundary state has strong robustness to structural defects such as corners. Using the third-order nonlinear effect of silicon dielectric—four-wave mixing, a pair of signal light and idle light can be prepared in an optical topological insulator. The research team proved that the signal light and the idle light generated in the optical topological insulator are continuously frequency entangled, and since the frequencies of the signal light and the idle light are located in the topological non-trivial band gap, the generated continuous frequency entangled two-photon state It is protected by topology and has strong robustness.
Realization of topologically protected continuous frequency entangled two-photon states in optical topological insulators
This research work applies novel topological boundary states to the quantum field, and simultaneously realizes the generation and topological protection of continuous-frequency entangled two-photon states in an optical topological insulator, providing a new research idea for quantum computing and quantum communication.
The work was independently completed by Shanghai Jiaotong University, with doctoral student Jiang Zhen as the first author, and associate professors He Guangqiang and Jiang Chun as the co-corresponding authors of the paper.
Paper link:https://doi.org/10.1515/nanoph-2021-0371
