The Chinese Academy of Sciences has successfully developed two high-precision scientific instruments

Recently, relevant experts of the Chinese Academy of Sciences held a "Instrument Acceptance Meeting" at the Institute of Physics of the Chinese Academy of Sciences, and the "In-situ Micro-Structure Analysis and Property Testing Joint System" and "Ultra High Vacuum Low Temperature" applied for by the International Quantum Structure Center in 2001. Strong Magnetic Field Dual-Probe Scanning Tunneling Microscope/Spectrum System” Two large instrument development projects were accepted.

After the on-site test conducted by the test expert group, the members of the acceptance expert group agreed that the successful development of these two large-scale instruments and equipment not only reached the international leading level in many indicators, but also achieved the original innovation goal, and cultivated a rare batch of rare achievements. The high-level technical talents have laid a solid foundation for the future research and development and sustainable development of large-scale instruments of the Chinese Academy of Sciences. At the same time, the project team provided complete documentation, complete information, reasonable use of funds, completed the contract task with high quality, and recommended that the competent department approve the project to pass the acceptance.

According to experts, in the pilot project of knowledge innovation project of the Chinese Academy of Sciences, the Institute of Physics, while introducing foreign advanced instruments and equipment, vigorously advocated the independent development and development of large-scale scientific instruments, providing platform guarantee for the realization of original innovation. In 2000, after the establishment of the International Quantum Structure Center of the Institute of Physics, in order to meet the needs of scientific research and utilize the talents of the quantum center, a large-scale scientific instrument development plan was formulated. The goal is to build two advanced precision instruments, and to require the world's most sophisticated instruments that are independently designed by China and have independent intellectual property rights and are not available on the market for five years.

After several years of efforts, the two large-scale instruments "in-situ micro-area structure analysis and property testing combined system" and "ultra-high vacuum low-temperature strong magnetic field dual-probe scanning tunneling microscope / spectrum system" have finally been successfully developed. This is of great significance for improving the level of research and development of precision instruments in China, promoting the transformation of scientific research results, and improving China's international competitiveness in this respect. At the same time, it will greatly improve the research ability of the quantum center, and promote the development of a variety of functional materials such as magnetic, semiconductor and superconducting, which have been widely used, to the nanometer scale, and to study at a higher level. The growth of these materials, the characterization of physical/chemical properties, the study of quantum effects, and the development of novel nano/quantum devices are of great importance.

In-situ micro-area structure analysis and property testing joint system

Studying new structures, new properties, and new device performance requirements for low-dimensional materials requires manipulation and measurement of individual nanostructures. The sample manipulation capability and measurement function of existing commercial equipment are difficult to meet the needs of scientific research and development. The development of advanced nanomanipulation and nanometer measurement instruments is an important basis for solving scientific frontier problems. Professor Wang Zhonglin, Researcher Wang Enge and Associate Researcher Bai Xuedong of the International Center for Quantum Structures of the Institute of Physics, under the strong support of the innovation fund of the Institute, developed a joint system for structural analysis and property testing of in-situ micro-areas, designed and manufactured scanning tunnels in high-resolution transmission electron microscopy. microscope.

TEM is a scanning probe navigation that combines the powerful structural characterization functions with nanomanipulation functions to achieve physical properties measurement of individual nanostructures and to characterize the microstructure of materials in situ. The device's probe adjustment range is on the order of millimeters with an adjustment accuracy of 0.1 nanometers. In addition to measuring the field emission properties and transport properties of individual nanomaterials, it can also measure mechanical and electromechanical properties and perform a variety of nanomaterial physics/chemistry. The study of the problem has the comprehensiveness and flexibility of the application.

In addition, according to the needs of scientific research and development, equipment can be modified at any time to meet new measurement needs, which is difficult to achieve for commercial equipment. The mechanical properties of nanosprings under free vibration, the field-emission properties of structure-resolved field emission and the properties of dynamic field emission have been studied using the developed equipment, and the first batch of experimental results have been obtained. The test expert group conducted a comprehensive test on the system. The results show that the equipment has reached the contract book index, and the research work has been carried out with the equipment, and important research results have been obtained. The system is equipped with a scanning tunneling microscope unit in a very limited TEM space. The position of the scanning probe is large and can be accurately positioned to achieve manipulation and physical property measurement for a single low-dimensional structural sample.

Physical phenomena are observed in situ in transmission electron microscopy, and the microstructure of materials is characterized at the same time. The novel physical properties of low-dimensional materials are studied, and the direct relationship between properties and structures is established. The system is an advanced large-scale nano-characterization instrument, which provides a powerful experimental method for carrying out scientific research on low-dimensional (nano) materials. Its successful development is of great significance for engaging in original research.

Ultra-high vacuum low-temperature strong magnetic field dual-probe scanning tunneling microscope/spectral system in situ systematic characterization of the optical, electrical and magnetic properties of nanostructures is a very important issue for nanotechnology. It includes two aspects, one is the ability to controlly prepare and grow nanostructures, and the other is the use of appropriate scientific instruments to accurately and accurately characterize the various properties, phenomena and processes of nanostructures.

Due to the existing commercial equipment or the lack of certain technical functions, or the difficulty of integration between different systems, the above needs cannot be met, and such an instrument system can only be developed independently according to specific research. In particular, the recent rise of spintronics and solid-state quantum information and computation has brought new functional requirements and more complex performance combinations to experimental instruments, and commercial instruments cannot meet the research needs.

In these new fields of research, if you can combine existing experimental techniques and develop new instrument functions organically based on the latest research ideas, it will definitely help the research work, and the key to doing this is Independent research and development of instrument systems and the core technology of the entire system.

To this end, Professor Chen Dongmin, Researcher Xue Qikun, and Associate Professor Liang Xuejin of the International Center for Quantum Structures of the Institute of Physics, under the strong support of the innovation fund of the Institute, began to develop the "Ultra High Vacuum Low Temperature Strong Magnetic Field Double Probe Scanning Tunneling Microscope/Spectrum System" from 2002. . The system mainly consists of three parts: low temperature and strong magnetic field double probe scanning tunneling microscope (STM), ultra high vacuum in situ sample preparation system, and ultrafast spectral measurement platform.

Considering the future expansion of the instrument, the probe and the sample holder are mounted on a structure that can be easily disassembled. The hardware ensures that other types of measuring devices can be replaced at any time for specific performance testing. On the other hand, the entire control The software and hardware of the system are all developed by themselves, which lays the foundation for further system transformation and upgrade. Under the premise of ensuring scientific research, they continue to expand their functions according to the needs of scientific research. Last year, the "ex situ weak signal testing system" was completed on this platform.

This year, they also received funding from the National Natural Science Foundation's Instrument Special Fund, and are developing an extreme condition dual-probe AFM system on the instrument platform to further expand the application area of ​​the system and maximize the use of existing resources. The test expert group conducted on-site actual tests on the system, and the results showed that the development equipment has basically reached and partially exceeded the mission indicators. The successful development of this system not only enables the controlled preparation and growth of nanoscale structures, but also the in-situ characterization of the optical, electrical and magnetic properties of nanostructures for spintronics and solid-state quantum information. Research in new fields such as quantum computing provides powerful experimental tools. This project is a successful example of China's independent research and development of high-precision scientific instruments.