The Ren Xifeng research team of this team cooperated with Dai Daozinc team of School of Optoelectronic Science and Engineering of Zhejiang University/State Key Laboratory of Modern Optical Instruments, and realized the operation of a two-bit quantum logic gate with on-chip waveguide mode coding for the first time. The related results were recently published in Physical Review Express.
Previously, Ren Xifeng Research Group and Dai Daoxin Research Group of Zhejiang University had long-term cooperation in the research of silicon-based optical quantum devices and chips, and made a series of important progress.
In 20 16, the above team used waveguide mode coding for quantum information processing for the first time in the world, and realized the coherent transformation between waveguide mode, polarization and path coding entangled States. In 20 19, the team realized the preparation of waveguide mode coded entangled light source for the first time. 202 1, based on the dense waveguide superlattice array, the team constructed the world's smallest optical quantum controlled NOT (CNOT) gate.
On this basis, two new multimode photonic devices, waveguide mode coupler (TMDDC) and mode attenuator (MMA), were independently designed and developed, which were used to realize specific mode-dependent coupling and mode-dependent attenuation functions respectively, and these new photonic devices were further integrated on a single chip, demonstrating the two-bit controlled ungated operation of waveguide mode coding for the first time in the world. In this experiment, the quantum controlled NOT-gate can entangle the quantum bits encoded by two waveguide modes, and the average fidelity is between 0.87 and 0.95438+0.
This achievement paves the way for quantum operation of waveguide mode coding, and can also be used for on-chip multi-degree-of-freedom optical quantum information processing, laying the foundation for realizing large-scale optical quantum systems. The reviewers of Physical Review Letters agreed that this is an important research work and spoke highly of it: "TMDDC and MMA, two newly invented devices, are very important" and "I believe this work will provide necessary tools in the corresponding research fields".
Professor Ren Xifeng from Key Laboratory of Quantum Information of Chinese Academy of Sciences, Professor Dai Daozinc from School of Optoelectronic Science and Engineering of Zhejiang University/State Key Laboratory of Modern Optical Instruments are co-authors, and Feng Lantian, special associate researcher of Key Laboratory of Quantum Information of Chinese Academy of Sciences, and Zhang Ming, assistant researcher of Zhejiang University are co-authors. This work is supported by the Ministry of Science and Technology, the National Foundation of China, China Academy of Sciences, Anhui Province and China University of Science and Technology.