Room-temperature superconductor Photo: IC

Topics about room-temperature superconductors have been spreading on Chinese social media amid a global wave of efforts to verify the synthesis of magnetic levitation-enabled LK-99 crystal, as Chinese, US and Russian research teams have rushed to replicate the work or post relevant papers after a research team from South Korea recently uploaded two scientific papers claiming to have discovered the "world's first room-temperature superconducting material."

However, several insiders reached by the Global Times stressed that regardless of the results from the South Korean team or the replicated experiments posted by other teams worldwide, they have only shown that the samples have certain properties of superconductivity, such as diamagnetism. Superconductivity is diamagnetic, but diamagnetism is not necessarily superconductivity, insiders noted.

Some of the insiders believe even if superconductivity can be achieved one day, its technical application still has a long way to go, possibly taking decades.

On Tuesday, a Chinese experimental team released a video on video sharing platform Bilibili, stating that they have successfully verified for the first time the synthesis of a LK-99 crystal that can be magnetically levitated. This crystal has a larger levitated angle compared to the previous sample obtained by the South Korean team. This development is expected to realize the true significance of non-contact superconducting magnetic levitation.

The Chinese team's leader, Professor Chang Haixin of Huazhong University of Science and Technology, confirmed to Chinese media outlet cls.cn on Tuesday night that the video was indeed from his team, which also includes postdoctoral researcher Wu Hao and doctoral student Yang Li.

The video has garnered more than 7 million views as of press time.

However, the video also stated that they have currently only verified the Meissner effect. Although this crystal exhibits diamagnetism, it is relatively weak and does not possess "zero resistance." Its overall behavior is similar to that of a semiconductor curve. The publisher believes that even if LK-99 has superconducting properties, they are only present in trace amounts of superconducting impurities, unable to form a continuous superconducting path.      

Previously, a research team from South Korea uploaded two papers on arXiv claiming to have discovered the "world's first room-temperature superconducting material," attracting attention from around the globe. It is reported that this material is mainly a modified perovskite crystal structure (referred to as LK-99), a type of lead phosphate with copper doping.

However, the team has faced skepticism due to the insufficient experimental data they have currently provided to prove LK-99 is a superconductor. Multiple research teams worldwide are attempting to synthesize LK-99 to verify the experimental results at the moment.

Yuan Lanfeng, a research fellow at Hefei National Laboratory for Physical Sciences at the Microscale, the University of Science and Technology of China, told the Global Times on Wednesday that the results from the South Korean team that have been claimed so far, if all accurate, can only prove that the material possesses a certain level of magnetic resistance. However, this does not imply the presence of superconductivity.

The replications of this experiment by China and Russia share a common flaw with the South Korean one, which is a lack of evidence that proves that this is a superconducting material, Yuan pointed out.

Zheng Dongdong, assistant professor with the School of Automation, Beijing Institute of Technology, also told the Global Times that so far it has only been proven that the experiment samples have some properties of superconductivity, such as diamagnetism. Superconductivity is diamagnetic, but diamagnetism is not necessarily superconductivity, he noted. 

So the next step is to verify whether the samples are actually superconducting, Zheng noted.

Superconductivity means that the resistance of the material is zero, Zheng said.

If room-temperature superconductivity can be realized, which means there is no need to use additional refrigeration equipment to maintain low temperatures, then its application can be greatly expanded, Zheng revealed.

Room-temperature superconductivity would enable long-distance lossless power transmission, leading to a new wave of global infrastructure development in the electricity network. Additionally, media reports suggest that breakthroughs are expected in areas such as superconducting magnets, superconducting cables, and superconducting maglev trains.

Yuan called for international cooperation in the field of superconductivity.