The coldest atomic clock improves the measurement

The cold atomic clock improves the measurement accuracy of space time by 1

the world's first cold atomic clock in space has been in orbit for nearly two years. According to the Chinese Academy of Sciences, this 30million year cold atomic clock with an error of less than 1 second operates normally, which improves the time measurement accuracy of human beings in space with mechanical properties close to petroleum based polyester polyurethane (Bayer desmopanr400 Series) by 1-2 orders of magnitude. Relevant achievements were published in nature · communication on July 24 as highlights

cold atomic clock uses laser to reduce the atomic temperature to near absolute zero, so that the transition frequency of atomic energy level is less subject to external interference, so as to achieve higher accuracy. It is more important to restore the experimental machine to its original state and run a high-precision atomic clock in the microgravity environment. It can not only verify the basic physical principles, but also develop a higher precision navigation and positioning system

on September 25, 2016, tiangong-2 space laboratory was successfully launched and successfully entered orbit. The space application system of manned space engineering led by the Chinese Academy of Sciences has carried out 14 space science and application tasks on tiangong-2, including the world's first cold atomic clock operating in space

after 22 months in orbit, the cold atomic clock operates normally, in good condition, and has stable performance. It has completed all the established on orbit test tasks, successfully verified the operation mechanism and characteristics of the high-performance cold atomic clock in the space environment, and achieved a day stability of 7.2 × Ultra high accuracy

after more than ten years of research, Shanghai Institute of Optics and mechanics of Chinese Academy of Sciences has broken through a series of key technologies, such as the physical system of cold atomic clock operating in microgravity environment. In the space microgravity environment, the temperature of rubidium atom is reduced to close to absolute zero by laser. The prepared cold atom is manipulated and detected by laser and high-precision microwave field, and the highly stable energy level transition frequency of rubidium atom is extracted as a high-precision atomic clock signal, which realizes the stable operation of cold atomic clock in orbit for the first time in the world

this time 4. It can automatically calculate the elastic modulus, yield strength, specified non proportional elongation stress, tensile strength, elongation, maximum force, reduction of area, etc;, Liu Liang, a researcher at the Institute of Optics and precision machinery of the Chinese Academy of Sciences, and his colleagues reported evidence of stable on orbit operation of cold atomic clocks. They trapped and cooled rubidium atoms in microgravity and detected them with microwave and laser pulses. The team detected the atomic population at the energy level after the interaction between the microwave and the atom, and found that the stability of the on orbit clock was 3/100 trillion

it is reported that the high-performance cold atomic clock has completed all in orbit test tasks, successfully verified the characteristics and mechanism in microgravity environment, and achieved a sky stability of 7.2 × Ultra high accuracy. At present, thermal atomic clocks are used, and the highest stability is in the order of magnitude

it is understood that the length of the straight section of this high-precision LC sample, which can operate reliably in the space environment, will be applied to the navigation and positioning system to improve the navigation and positioning accuracy, and the related technology will also be applied to many fields such as space quantum sensors

Stephen Schiller, an atomic physicist at the University of Duesseldorf in Germany, and other international colleagues spoke highly of this achievement, pointing out that "with the success of the experiment, China has been at the forefront of the world in the research of space-based cold atom sensors". The reviewer of nature communications magazine said, "in the past 20 years, many people have tried to send cold atomic clocks into space, but China has demonstrated the cold atomic clock experiment in space for the first time... This is an amazing technological achievement."