What pushed Chinese physicists to the forefront?

Author:High Energy Institute of the C Time:2022.06.22

Written article | Creek

More than 230 years ago, an idea from the genius brain caused the continuous development of a certain technology. Now this technology has deeply affected the entire world. What happened during this period? The ups and downs of stories are divided into five spaces. This is the fourth.

In 1789, a brain imagined from French chemist Lawari genius: "If the earth is sent to a very cold area ...". This idea inspired the scientific community to continuously explore various methods to achieve gas liquefaction. By July 1908, Angnens in the Netherlands successfully completed the world's most liquefied beefized liquefaction, and all the gas in the world can be liquefied. , Lavisi's idea has finally become a reality.

In 1911, Angnees discovered magical superconductivity, but until 1957, the BCS theory founded by Badin, Cooper and Schryphon in the United States explained the superconducting phenomenon perfectly from the micro.

The cost of low temperature conditions required for superconductivity is very high, which has greatly restricted its application. The scientific community strives to find superconducting materials with higher critical temperatures, and there is a "McMlan limit" that puts related research into trouble. No one expected that a research boom was suddenly set off in the 1980s, which caused a rare and rare competition, and Chinese scientists overcome difficulties and made important contributions.

After the climax, the relevant research fell into a trough again, until an unexpected discovery caused a new wave, but this time it pushed Chinese physicists to the forefront!

The outbreak after silence

In 1994, the Zhu Jingwu team in the United States set the highest record in the world at that time: the superconducting critical temperature of the mercury and calcium and copper oxygen system under high pressure reached 164 k (135 K under the normal pressure). Since then, this record has not been broken for a long time, and the scientific community's exploration of high -temperature superconducting materials has fallen into a trough again. In the past ten years, the research of high -temperature superconductors has basically stayed in the field of copper -based compounds. Iron -based compounds were ignored by most researchers due to its magnetic factors. Until 2008, an unexpected discovery of Japanese scientists triggered a new wave of high -temperature superconducting research.

Japan 26K

The Hideo Hosono team of Tokyo University of Technology in Japan accidentally discovered that the latch phosphor oxygen (lafepo) system material was superconductive during the study of transparent conductive oxide materials in 2006-2007. about. Because the critical temperature of 3 K is not high, the news did not attract widespread attention at the time.

The Hoshino Hideko team realized that there may also be superconductivity in the Lafeaso compounds. This compound is stacked by the non -conductive oxidation of the oxidation and the conductive arsenic iron layer. Among them, the oxygen, they tried to replace part of the oxygen ions to fluor (F) ions, trying to use the method of regulating fluoride ion concentration to obtain a new super conductor of the superconducting critical temperature of 26 K.

On February 18, 2008, the Japanese science and technology revitalization agency and Tokyo University of Technology jointly issued a news bulletin, announcing that the Hosano Hideko team discovered the new type of high -temperature superconducting material -fluoride muddy oxygen arsenids Superconducting characteristics (January 9th, "JACS), submitted the paper" Iron-Based Layered SuperConductor La [O1-XFX] Feas (x = 0.05-0.12) with TC = 26 K ", February 23 The day was officially published).

Hideo Hosono (picture from the Internet)

Hoshino Hideyoshi and other papers submitted in January 2008 (pictures are from the Internet)

China 43K

The Chinese research team during this period was completely different from the situation in 1986. Based on the country's attention and stable support for laboratory equipment construction and excellent talent reserves over the years, and the accumulation of team scientific research experience has improved, the research strength has greatly improved. At that time, various research teams in various domestic units were conducting high -temperature superconductors. Some research teams made progress in the preparation of non -doping single crystals in the oxygen oxygen.

On February 18, 2008, it was reported that after the Japanese team obtained the superconducting critical temperature of 26 K 镧 oxygen arsenide, because the iron -based compound was once considered to be the restricted area of high -temperature superconductors (its magnetic factors), research in many countries, research in many countries The team is still watching and hesitant. However, the Chinese research team realizes that there is a series of high -temperature superconductors in similar structures with keen insights that there are a series of high -temperature superconductors in similar structures, which quickly carried out its own characteristics.

On March 25th and 26th, 2008, the team of Xian-HUI Chen, the University of Science and Technology of China, and the Institute of Physics, Nan-Ling Wang, were independent of fluoridal doped oxygen arsenic (SMOFEAS) and olive oxygen arsenic. The compounds (CEOFEAS) observed 43 k and 41 k superconducting temperature, breaking the "McMlan limit", and the first proved that the iron -based superconductive is an informal high -temperature superconductor.

陈仙辉团队向《Nature》提交了论文“Superconductivity at 43 K in Samarium-arsenide Oxides SmFeAsO1-xFx”，王楠林等向《Physical review letters》提交了论文“Superconductivity at 41 K and its Competition with Spin-Density-Wave Instability in layered CEO 1 -X F X Feas ". Chen Xianhui and Wang Nanlin (the picture is from the Internet)

Chen Xianhui and others submitted to "Nature" (the picture is from the Internet)

Wang Nanlin and others submitted to "Physical Review Letters" (picture from the Internet)

China 55K

Immediately afterwards, the Chinese team first discovered a series of iron -based compound supercondules that exceeded 50 K in the superconducting critical temperature. The Zhao Zhongxian team of the Institute of Physics found on March 28, 2008 that the superconducting critical temperature of the fluoridal blealing oxygen arsenic compound can reach 52 K, creating a new record.他们立即向《Materials Research Innovations》提交了题为“Superconductivity at 52 K in iron2based F2doped layered quaternary compound PrO1 - x Fx FeAs”的论文，向《Europhysics Letters》提交了题为“Superconductivity in iron-based F-doped Layered Quaternary Compound ND [O1-XFX] Feas ".

On April 13, Zhao Zhongxian's team also found new discovery: under pressure conditions, the superconducting critical temperature can be further increased to 55 K under pressure conditions, that is, the "Chinese Physics Express English version" was submitted to the "Chinese Physics Express" version entitled to be entitled "SuperConductivity at 55 K in Iron-Based F-DOPED LAYERED Quaternary Compound SM [O1−xfx] Feas".

The Haihu team heard by the physics synthesized the world's first cave -based iron -based superconductor -锶 mixed with oxygen arsenide compounds. There are many similar high -level experiments in domestic teams ...

Zhao Zhongxian and others submitted to Materials Research Innovations (picture from the Internet)

Zhao Zhongxian and others submitted to "Europhysics Letters" (picture from the Internet)

The paper submitted by Zhao Zhongxian and others to the English Edition of China Physics Express (picture from the Internet)

After more than 20 years of silence, the second upsurge of looking for high -temperature superconductors was the introduction point of Japanese scholars discovered the iron -based superconducting sample with a superconducting critical temperature of 26 K. When many scholars were suspicious, the reaction of the Chinese research team surprised the whole world. Like the outbreak of the volcano, they have continuously obtained a series of superconducting critical temperatures in a very short period of time to break through the high -quality iron -based compound of McMlan's limit, and the record of superconducting critical temperature has been continuously updated. Super conductor) was born.

China-the forefront

On April 25, 2008, "Science" reported the "New SuperConductors Propel Chinese Physicist To Forefront" with "SCIENCE". Leading work of important influence. Important journals such as "PHYSICS TODAY" also reviewed the progress of the Chinese research team's iron -based superconducting research. The "Iron -based High -temperature Superconductor Research" has been rated as one of the top ten scientific progress of the world in 2008 by many international media.

Evaluation article published in "Science" in April 2008 (picture from the Internet)

In May 2008, "Physics Today" tracking reports on iron -based superconductors (pictures are from the Internet)

Iron -based high -temperature superconductors have the characteristics of small resistance at normal temperature, large critical current, and low cost. It is very beneficial to the application prospects of superconducting technology. The breakthrough progress made by Chinese scholars is of great significance. In this second upsurge, Chinese scholars, as a strong player, have promoted many research teams at home and abroad. The Chinese research teams have been published in important journals in the world. Related results have been highly evaluated by the international scientific community and were reported by multiple internationally renowned journals as highlights.

(Note: According to the statistics of the world's authoritative scientific and technological literature retrieval system "Sci (SCIENCE CITATATATATAATIONITION)", on January 4, 2013, Chinese scholars' 8 representative papers on iron -based superconducts SCI quoted 3801 times, 20 main articles, 20 main articles, mainly 20 main articles. The paper sci he quotes 5145 times.) New ideas

The second upsurge of finding high -temperature superconducting materials has caused the international high -temperature superconducting research to inspire new vitality. The mystery of the micro -mechanism of high temperature superconducting has gradually been revealed. The space for research has been greatly expanded. Can achieve room temperature superconducting as soon as possible and make it widely applied.

American-prophecy

Some people have proposed: Can hydride become superconducting materials for room temperature? The earliest proposal was Neil Ashcroft, Cornell University in the United States. He was based on BSC theoretical analysis and calculation. The room temperature superconductor, the superconducting critical temperature can reach 290 k, his paper "Metallic Hydrogen: A High-Temperature SuperConductor?" In "Physical Review Letters" on December 23, 1968. Because the required high -pressure conditions are generally difficult to achieve, some research teams imagine to replace solid hydrogen with hydrogen -rich materials, thereby reducing the required pressure conditions.

Neil Ashcroft (picture from the Internet)

The paper published by Ashcrov in 1968 in "Physical Review Letters" (picture from the Internet)

In 2004, after more than 30 years of research, Ashcrovt proposed that some hydrogen -rich compounds, such as methane, methane, ammonia, etc. can become a super conductor of high crowded temperature under lower pressure conditions. His paper can be. "Hydrogen Dominant Metallic Alloys: High Temperature SuperConductors?" Published on May 7, 2004, "Physical Review Letters". Ashcrovt's prediction has not been verified.

The paper published by Ashcrov in 2004 in "Physical Review Letters" (picture from the Internet)

China-prophecy

In 2014, two research teams in China made new predictions in terms of computing analysis based on BSC theory, and their research results quickly received the attention of the international high temperature super -guided world.

The Ma Yiming team of Jilin University predicts that under 160 GPA (Gap) high -pressure conditions, hydrogen sulfide (H2S) can be transformed into superconductors, superconducting critical temperature is 80 k, and the paper "The Metallization and SuperConductivity of Dense Hydrogen Sulfide" was published in 2014. "Journal of Chemical Physics" on the 7th.

Jilin University Cui Tian team prediction: Under 200 GPA (Gpa) high -pressure conditions, H3S structure materials composed of hydrogen sulfide (H2S) and hydrogen (H2) can be transformed into superconductors, superconducting critical temperatures from 191 k to 204 k In the between, the paper "Pressure-InDuced Metallization of Dense (H2S) 2H2 with High-TC SuperConductivity" was published in "Scientific Reports" on November 10, 2014.

Ma Yiming, Cui Tian (picture from the Internet)

Ma Yiming and others published in "Journal of Chemical PHYSICS" in May 2014 (picture from the Internet)

Cui Tian and others published in "Scientific Reports" in November 2014 (picture from the Internet)

Germany 203K

Theoretical prophecy has played a role in guiding and encouraging experimental research. At the end of 2014, Mikhail Eremets team from the Map Chemical Research Institute of Germany confirmed the predictions of Cui Tian, Ma Yiming and others through experiments, and obtained the superconducting critical temperature of 190 K under high -pressure conditions. Sulfide structural material. Hydrogen sulfide is a traditional superconductor. It is generally believed that it is impossible for hydrogen sulfide to play its superconductivity at higher temperatures. The experimental results obtained by Eretamez are of great significance.

In May 2015, Eredersz was a new breakthrough. Under the high pressure of 170 GPA (Gipa), the superconducting critical temperature of the hydrogen sulfide structural material was increased to 203 K, which once again created a new record of room temperature superconducting. Their paper "Conventional SuperConductivity at 203 Kelvin at high Pressures in the Sulfur Hydride System" was published in "Nature" on August 17, 2015. This experimental result requires a considerable high pressure conditions. Although the practical value is not large, it is inspiring. The room temperature superconducting (ie 273 k) under high -pressure conditions is likely to be realized in the near future. Mikhail Erees (Mikhail Eremets) (picture from the Internet)

Eramez et al. Paper published in "Nature" in August 2015 (picture from the Internet)

How to explain the breakthrough in the Eretz team experiment that caused the relevant theoretical discussion boom. Multiple research teams predict whether there are other materials in the same way to generate superconductivity in the same way at high temperatures. Among them Including the hydrogenation of the Ericmez team is studying.

American-prophecy

In 2017, a cooperative research team in Washington Cunki made predictions from structural analysis: hydrogenation (LAH10) may become a superbctive critical temperature superconductor under high-pressure conditions. Their papers "POTENTIAL HIGH-TC SuperConduction Lanthanum and Yttrium Hydrides AT High Pressure "March 20, 2017, submitted to the" Proc. Natl. Natl. Acad. Sci. U.S.A.) "2017 and was officially published on June 19.

The paper submitted to the "Academy of Sciences" in March 2017 to the Carnegie team (picture from the Internet)

China-prophecy

In 2017, the Chinese Ma Yiming team made new theoretical predictions by calculating: the hydrogen of rare earth elements can become superconductors under high pressure, and the critical temperature can be higher than that of hydrogen sulfide. Their papers "Hydrogen Clazrate Structures in Rare Earth Hydrides at high Pressures: POSSIBLE ROOM-TEMPERCONDuctivity" submitted to "PHYSICAL Review Letters" on May 11th.

Ma Yiming and others submitted to "PHYSICAL Review Letters" in May 2017 (picture from the Internet)

China-New direction

In 2017, Cao Yuan, a Chinese student who was studying at Massachusetts Institute of Technology (MIT), found in the experiment that two layers of graphene (two -dimensional carbon nanomaterials) were stacked together and a slightly off -1.1 degree angle would produce superconducting Effect (known as the magic angle), the superconducting critical temperature is 1.7 k. This is the first time in the world to discover superconducting graphene to achieve superconducting. After repeated experiments, Cao Yuan established a comprehensive theory of graphene conduction, which opened a new direction for superconducting physics and coagulative physical physics research. He and the instructor published two articles in "Nature" on May 6, 2018 (Cao Yuan is the first author): "Tunable Correled States and Spin-Polarized Phases in Twisted Bilayer – Bilayer Graphene", "MAPPING The TWINGLE Disorder and Landau Levels in Magic-Agle Graphene ". To this end, Cao Yuan appeared on the top ten scientists of the 2018 "Nature".

Cao Yuan (picture from the Internet)

Cao Yuan et al. Published two papers published in "Nature" on May 6, 2018 (picture from the Internet)

U.S.-room temperature under high pressure superconduct

In 2020, the Ranga Dias team of the University of Rochester was inspired by the organic superconducting theory of William Little, Stanford University. In 1964, Litt was calculated through the model he founded (the Little model): organic compound molecules may also have superconductivity, and the superconducting critical temperature may be higher than the room temperature (his paper "POSSIBILITY of Synthesizing An Organic SuperConductor "" PHYSICAL Review "on June 15, 1964).

William Little (picture from the Internet)

Lotter's paper published in "Physical Review" in June 1964 (picture from the Internet) in July 2020, the Dias team made amazing progress. They combine hydrogen -rich materials with organic superconductors and use carbon elements (ordinary elements in nature) instead of metal elements in the ternary compound. The room temperature superconducting. They use the three yuan compounds of carbon sulfur (C-S-H) (different from li-Mg-H) proposed by Ma Yanming's team, and the superconducting critical temperature is 287.7 k (15 degrees Celsius). This is in human history The first superconductor that across the 273 K node was achieved at room temperature, which was a milestone. Their papers "Room-Temperator SuperConductionivity in A Carbonaceous Sulfur Hydride" was published in "Nature" on October 14, 2020.

Ranga Dias (picture from the Internet)

The paper published in "Nature" in "Nature" in October 2020 (picture from the Internet)

Conclusion

Since the 1960s, the scientific community has been working hard to find superconducting materials with higher critical temperature and more suitable for practical applications. In the decades, there were orgasm and climax, and Chinese scientists lived up to make significant contributions. The room temperature superconducting under the conditions of millions of times of atmospheric pressure is currently difficult to say that there is any practical application, because even from the perspective of basic research, only a few laboratories in the world can achieve such pressure conditions. It is expected that the scientific community can get superconducting materials at the temperature of the normal pressure room as soon as possible, and truly benefit all human beings.