The research group of Professor Zou Changling of the academician Guo Guangcan of the University of Science and Technology of China proposed a new principle and a new scheme for achieving photon blocking by using extremely weak optical nonlinearity in a single optical mode, and analyzed the experimental feasibility of its implementation on an integrated optical chip. The results were recently published in the Physical Review Letters.
Photon blocking in single-mode nonlinear optical cavity Research group courtesy of the group
Nonlinear interactions between single photons are the core resource for scalable optical quantum information processing at room temperature. However, due to the nonlinear polarization rate and optical loss of the material, it is extremely difficult to directly observe the photon interaction at the single photon level in the nonlinear optical system, so the traditional single photon generation method mainly relies on probabilistic parametric downconversion and requires high pump optical power.
Zou Changling’s research group has been committed to the research of integrated photonic chip quantum devices in recent years. On the integrated chip, the nonlinear optical effect can be greatly enhanced by the micro-nano optical structure. Based on the nonlinear optical effect of microcavitability enhancement, physical and applied research with few photons or even single photons is carried out. Previously, in 2020, the use of photon second-order nonlinear implementation of deterministic, high-fidelity photon-photon quantum phase gate is expected to achieve scalable quantum information processing at room temperature without atoms, superconducting bits and other components.
Recently, the international integrated nonlinear photonics experimental research has made rapid progress, with lithium niobium niobate, indium gallium phosphide and other materials as the representative platform has increased the single photon non-simple harmonicity of the optical mode to the order of 1%, providing a new way to achieve weak light quantum effects at room temperature. However, the structure required for these research protocols is complex and difficult to achieve based on existing experimental conditions. In addition, kinetic blocking in single-mode cavities is less effective and the physical mechanism is unclear.
In view of the above problems, the research team introduced the frequency freedom of photons and proposed to use two continuous laser beams to control their dynamic evolution in a single optical mode. By using the non-linear cavity to non-uniform response to different frequency drives, the distribution of the number of houses in different photon states is precisely adjusted at a specific time, and the suboperzon quantum statistical light field is generated with high fidelity. Based on the experimental parameters of the integrated lithium niobate chip that have been reported, the researchers demonstrated the experimental feasibility of the protocol.
Reviewers agreed that the study introduced entirely new physical mechanisms that revealed the physical nature of kinetic photon blocking. It is the simplest and consumes the least resources in the relevant studies that have been reported. (Source: China Science Daily Wang Min)
Related paper information:https://doi.org/10.1103/PhysRevLett.129.043601