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Source: Nature Series
作者：Nature Portfolio
The comprehensive extreme conditions experimental device can provide extreme conditions such as extremely low temperature, strong magnetic field and ultra-high pressure for the exploration of amazing new materials.
A comprehensive extreme conditions test facility located on the outskirts of Beijing that allows for a series of physical tests on samples. Image source: Institute of Physics, Chinese Academy of Sciences
Beijing
There are several nondescript buildings on the outskirts of Beijing marked with the letter "X", which stands for "extreme". This is the Integrated Extreme Conditions Experimental Setup (SECUF). Researchers around the world have subjected experimental materials to extreme magnetic fields, pressures, and temperatures, using new techniques to obtain observations with high temporal resolution.
The Integrated Extreme Conditions Experimental Facility cost up to $220 million. Finding a new superconductor with zero resistance is one of the goals that many researchers here dream of. Lu Li, a condensed matter physicist at the Institute of Physics of the Chinese Academy of Sciences and chief scientist of the Integrated Extreme Conditions Experimental Facility, said: "The combination of different extreme conditions is conducive to researchers making new discoveries. ”
A deep understanding of the superconductivity mechanism is essential as research institutes around the world race to develop materials that exhibit superconducting properties at room temperature rather than at low temperatures. Room-temperature superconducting materials offer great advantages, such as increased computer computing speed and reduced power consumption.
In extreme environments, a wide range of materials exhibit properties that would not be exhibited under normal conditions. For example, some seemingly ordinary materials can become superconductors under high pressure and low temperature conditions. Konstantin Kamenev, a physicist at the University of Edinburgh in the United Kingdom who works on extreme conditions engineering and instrumentation, said that measuring superconductivity properties is not an easy task, and the emergence of such properties is also related to measurement technology. The Integrated Extreme Condition Setup provides a variety of extreme conditions simultaneously, allowing researchers to characterize samples more comprehensively and efficiently. Cheng Jinguang, a condensed matter physicist at the Institute of Physics, said: "It's like a one-stop shop. ”
Limit Conditions Toolbox
In September last year, after a year of trial operation, 22 experimental stations of the Comprehensive Extreme Conditions Experimental Device were put into full operation. In the corner of the bright room is the experimental station that Cheng Jinguang is in charge of. The experimental station combines a cubic six-sided anvil pressure chamber (a device that exerts enormous pressure to squeeze material on six sides) and two sets of superconducting magnets and a helium-based cryostat. The station can be used to measure a range of electronic properties of materials. According to Cheng Jinguang, traditional high-pressure devices such as diamond anvils can accommodate samples equivalent to the width of a human hair, but the six-sided anvil of the combined extreme conditions experimental device can be used to compress larger samples, making it easier to achieve fine observation of electronic characteristics.
Cheng said that he and his colleagues have used the device to discover several types of superconductors, including a rare magnetic superconductor [1] and a manganese-based superconductor [2].
The Quantum Oscillation Experiment Station consists of two superconducting magnet systems that can simultaneously provide an ultra-low temperature environment. Image source: Institute of Physics, Chinese Academy of Sciences
Behind the yellow warning sign on the other side of the room is a powerful system of superconducting magnets. This is an experimental station built by condensed matter physicist Zhou Rui and his colleagues at the Institute of Physics for nuclear magnetic resonance research at extremely low temperature and strong magnetic fields. The station tracks and measures the movement of atomic nuclei in strong magnetic fields, helping to uncover the superconductivity mechanism of high-temperature superconductors with critical superconducting temperatures above -195.8 °C.
For example, the hybrid magnet composed of a superconducting magnet and a resistive magnet at the National High Magnetic Field Laboratory in the United States can produce a magnetic field of up to 45T, which holds a world record. The resistive magnets of the French National Laboratory of High Magnetic Fields have a magnetic field strength of up to 37T, and these magnetic fields have high energy consumption. According to Zhou Rui, the energy consumption of the comprehensive extreme conditions experimental device is much smaller than that of other experimental devices, so its steady-state magnetic field maintenance time is not a few hours or days, but up to a month, so that researchers can carry out experiments on samples for a longer time.
The six-sided anvil pressure chamber is placed against the wall, and the black and yellow warning signs are pasted on the surface. Compared to other high-pressure devices, it has a larger sample holding space. Image source: Institute of Physics, Chinese Academy of Sciences
There are also magnet systems that can be used to carry out other superconductivity studies. The experimental station led by Li Gang, a condensed matter physicist at the Institute of Physics, combines extremely low temperatures with 30T and 20T superconducting magnets to measure quantum oscillations, a physical phenomenon that can be used to draw electronic "fingerprints" of materials. Last July, condensed matter physicist Alexander Eaton and colleagues at the University of Cambridge in the United Kingdom spent two weeks using the station to reveal the electronic properties of the rare superconductor uranium ditelluride [3]. "It's the only place where we can do what we want to do," Eaton said. ”
Diverse combinations
Superconductivity researchers can use a variety of techniques in a comprehensive extreme conditions experimental setup. Guanghan Cao, a condensed matter physicist at Zhejiang University, and his colleagues used a six-sided anvil pressure chamber and nuclear magnetic resonance measurements to study an interesting chromium-based material that had been accidentally discovered. Cao Guanghan and colleagues placed the material in a six-sided anvil pressure chamber and found that the material could exhibit signs of superconductivity in a high-pressure environment [4]. They also used the NMR station to observe the magnetic properties of the compound. Experimenting with samples using multiple techniques in the same location can help researchers expand their depth and increase efficiency. Cao Guanghan said: "It's too convenient for us. ”
In the Integrated Extreme Conditions experimental setup, the phenomenon of superconductivity is not the only goal of the researchers. Some researchers use ultrafast light fields to explore the properties of semiconductors, while others use a range of instruments to trace the elusive quantum states of matter. Cheng Jinguang said that the experimental device is open to domestic and foreign users, and all applications will be treated equally. He added that this year's approval process will be more stringent to give researchers more time to work at the stations.
While the device can be used by researchers around the world, Ali Bangura, a condensed matter physicist at the National Laboratory for High Magnetic Fields, believes it gives China an edge in room-temperature superconductivity research. He said that providing more technical means to carry out observations in the same laboratory "greatly increases the likelihood of a major breakthrough for SECUF." ”
Bibliography:
1.Yang, P. T. et al. Nature Commun. 13, 2975 (2022).2.Liu, Z. Y. et al. Phys. Rev. Lett. 128, 187001 (2022).3.Weinberger, T. I. et al. Preprint at arXiv https://doi.org/10.48550/arXiv.2403.03946 (2024).4.Liu, Y. et al. Preprint at arXiv https://doi.org/10.48550/arXiv.2309.13514 (2024).
原文以Superconductivity hunt gets boost from China’s $220 million physics ‘playground’标题发表在2024年4月29日《自然》的新闻版块上
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Doi: 10.1038/d41586-024-01192-4