Researchers Achieve Quantum Sensor Of Electromagnetic Field In Nano Space

Academician GUO Guangcan's group has made important progress in the research of practical quantum sensors. Besides, SUN Fangwen's team experiment has realized the multi-functional quantum sensor with a high accuracy of 50 Nano space. This series of research results had published in the authoritative journal of Applied Physics physical review applied.

Micro Nano optoelectronic technology has become one of the core technologies in the field of information, it also plays an important role in energy, environment, biomedicine and other fields. In general, micro Nano optoelectronic devices have the advantages of small size, low electromagnetic field strength and easy to be interfered. Therefore, the micro and Nano electromagnetic field detection technology need to solve the problems and challenges of high spatial resolution, high measurement sensitivity and non-destructive measurement at the same time. SUN Fangwen's team in the laboratory focused on the challenges and difficulties in the measurement of micro and Nano electromagnetic fields. New ideas and methods, such as quantum sensors and quantum probes, were proposed to develop a new far-field optical super-resolution imaging technology with nanometer spatial resolution. Combined with the high fidelity quantum state control technology, the micro Nano electromagnetic field measurement technology has achieved the requirements all above.

SUN Fangwen's team first proposed and achieved charge state depletion nanoscopy (CSD) with nanometer spatial resolution and ultra-low pump power based on the control of charge state in the nitrogen-vacancy core of diamond, and realized the imaging and detection of electron spin quantum state with 4.1 nanometer spatial resolution. The imaging resolution obtained by the experiment is 1 / 86 of the optical diffraction limit, which exceeds the accuracy of 1 / 67 obtained by the simulated emission completion microscopy (STED, 2014 Nobel Prize in Chemistry). The pump power used is only 1 / 1000 of the stem imaging, and it is expected to be used in the biological detection in vivo. This work was published on Phys. Rev. Appl. 7, 014008 (2017), and was selected as the current editorial recommendation paper. In addition, time gating technology is proposed to improve the contrast of imaging signal and complete high contrast quantum imaging. The work published on Phys. Rev. Appl. 11, 064024 (2019). Furthermore, the combination of CSD Nano imaging technology with fluorescence lifetime imaging, optical polarization detection, electronic spin state high fidelity quantum manipulation technology has realized the non-destructive measurement of the optical field density of state, polarization, current and magnetic field generated by the metal nanowire structure. The spatial resolution is up to 50 Nano space. Because of the improvement of spatial resolution, the detection accuracy of the micro Nano electro-optical magnetic field is more than 96%. This work was published on Phys. Rev. Appl. 12, 044039 (2019).

This series of work has laid the foundation for high spatial resolution nondestructive electromagnetic field detection and practical quantum sensor. It will be applied to the detection of micro Nano electromagnetic field and photoelectron chip, as well as the research of interaction between micro Nano electromagnetic field and matter. In addition, compared with the high spatial resolution imaging of biomolecules, this work also broadens the application scenarios of far-field super-resolution imaging technology.

The first author of this series of papers is CHEN Xiangdong, associate researcher of the Key Laboratory of Quantum Information, CAS. The Ministry of Science and Technology, the National Foundation Committee, CAS and Anhui Province supported the above research.