Source: Xinzhiyuan

Last night, the news that “the LK-99 was officially counterfeited by South Korea and is not a room temperature superconductor” began spreading online.

However, in reality, the agency did not actually get a sample; it was just a conclusion reached after studying the paper data and video. Also, other Korean universities have begun their own replication research.

Just then, Huyntak Kim, the Korean team's second paper, released the second LK-99 half-levitation video. He also very much welcomed the resurgence of the LK-99 craze around the world, so we will wait and see.

Today, the Chinese University of Science and Technology team and India's CSIR team both published articles on arXiv, concluding that both of them were quite positive — LK-99 materials have great potential to be superconducting.

The Spanish team published an article explaining why it is so difficult to reproduce LK-99: LK-99 is a multi-phase heterogeneous structure with coexisting non-superconducting components, so the measurement results are very confusing.

In response, Station B's UP owner “kiiy_SS” concluded: It can be said that now we are far from actually proving superconductivity, and we are still far from actually proving superconductivity, and the three hurdles of quantum locking, thermal volume transition, and zero resistance.

A second maglev video appears

HuynTak Kim, a professor at William & Mary University in the US, provided the “New York Times” reporter with a second video showing the levitability of the LK-99.

As you can see, this sample is different from the sample in the first video; it has a semi-uniform rectangular shape.

However, in the first video, the original sample was clearly cut through, so the suspension section was much thinner than the rest of the sample.

This is a positive sign, which indicates that either the Korean team has multiple samples, or that they are capable of reproducing the sample and can find suspended properties on more than one sample.

In other words: the firing of the original sample was not due to chance; it cannot be reproduced again.

However, there are also netizens who falsify: as many people say, this kind of video can be made with an ordinary magnet.

Obviously, Professor HuynTak Kim did not fully consider how to use video presentations.

In contrast, in the “Guanshanguchi Male Technician” video of Huaxin University of Science and Technology, the magnet was replaced in a different direction, yet the sample was still subject to repulsion. This ruled out the possibility of magnetic materials, and the insulation was also a new type of antimagnetic material.

Three Korean papers: LK-99 may only be a superconductor

Yesterday, HuynTak Kim, a professor at William & Mary University in the US, was interviewed by Korean media via email.

In an interview, he said for his team: “By the time they saw the data, the verification of the superconductivity of the material had already been completed.”

In response to questions from reporters during the interview, he said, as shown in the LK-99 paper, the anti-magnetism of LK-99 is much greater than graphite (graphite), adding that “it cannot be explained unless superconductivity is used to explain it.”

He also stressed to reporters that they plan to present relevant content at the American Physics Conference to be held next year.

As for the replication and verification activities of the outside world, he said that although their own verification has already been completed, the participation of the outside world is also meaningful.

Their current focus is on further research and development of new materials, not on verifying whether LK-99 can actually superconduct at room temperature at room temperature.

The implication is that what we should write is very clear in our paper, and the data we have measured has proven that LK-99 is a superconducting material at room temperature at normal pressure. We are now already working on the next steps.

But if you want me to take it out now, I'm sorry, “it's too advanced, so it's not easy to show for now.” It depends on the American Physical Society next year.

As for the outside world's reproduction and verification requirements, we have no way to control it for the time being.

Finally, the interview also mentioned the “LK-99 Verification Team” set up by the Korea Low Temperature Superconductivity Association. According to existing papers, it is believed that LK-99 cannot be said to be a room temperature atmospheric pressure superconducting material.

They hope the Korean team will provide their own material samples for cross-testing as soon as possible.

Meanwhile, according to Yonhap News Agency, Park Jin-ho, vice-president of the University of Energy Technology, said, “We synthesized a sample of LK-99 a month ago, and it is still being analyzed continuously.”

Furthermore, he believes that even if LK-99 is not a room temperature superconductor, it can function as long as it exceeds the characteristics of existing materials.

The Korean Society: Currently, it is impossible to prove that it is superconductivity at room temperature

Also, yesterday, Yonhap reported that the “LK-99” verification team set up by the Korean Society of Superconductivity and Low Temperature Physics (KSSC) stated that the Korean team's paper cannot be concluded that LK-99 is a room temperature superconductor.

However, as to why the Korean verification team was only able to pass thesis research, it was because they did not get any samples from the original Korean team.

(1) According to the data published in the two papers and the published video analysis, this material cannot yet be considered superconducting at room temperature.

(2) If the team provides a sample they have manufactured, the verification committee will then measure and verify whether it is a room temperature superconductor. Participants' institutions include Seoul National University, Sungkyunkwan University, and Pohang University of Science and Technology.

(3) In addition to the samples provided, the Quantum Materials Superconductivity Research Team at Sungkyunkwan University, the Superconducting Materials and Applications Laboratory at Korea University, and the Composite State Research Team at Seoul National University are also conducting reproducibility studies of LK-99.

Three more new papers were published today

Up to now, two more LK-99 related papers have appeared on arXiv.

One article comes from the Huake University team. They said they are optimistic about the material potential of the LK-99.

The other article comes from a Spanish team. They believe that LK-99 is most likely a heterogeneous compound, and even if XRD is similar, it doesn't mean the product is the same.

The Chinese University of Science and Technology paper has been published

On August 1, “Guanshankou Male Technician”, the owner of the Huaxin University of Science and Technology, uploaded a video on Station B and discovered the antimagnetic phenomenon of LK-99 materials.

As soon as the video came out, it directly blew up circles at home and abroad. Netizens watched history in unison.

Today, a new paper on the course of this video experiment came out

Paper address: https://arxiv.org/pdf/2308.01516.pdf

Similarly, this paper made it to the top of the list of well-known foreign platforms.

In the paper, the author once again pointed out that the team successfully verified and synthesized the LK-99 crystal for the first time. At room temperature, this crystal has a larger levitation angle than the Korean team's sample.

The University of China Science and Technology has adopted the preparation system through the solid phase method

LK-99 sample.

In the following figure a, they are shown separately from left to right

,

The crystals, as well as the synthesis temperature curve of the target product LK-99, were all carried out at 10^-2 Pa.

In b and c, there are photographs of the synthetic LK-99 crystals, as well as optical micrographs. D shows the crystal structure of LK-99, of which 4

One of the atoms is replaced by a Cu atom.

In the figure below, a shows the thermomagnetic curves of sample 1 (macroscopic gray-black block) and sample 2 (micron crystals screened by magnetic repulsion, triangular shape, side length about 120 μm, thickness about 20 μm) measured in the physical properties measurement system (PPMS, DynaCool, Quantum Design).

For sample 1, the ZFC curve and FC curve showed antimagnetic transitions at ~ 326k and ~ 299K, respectively. This is similar to what Sukbae Lee previously reported.

However, the antimagnetic transformation temperature of the micron crystal sample 2 screened by magnetic repulsion was about 340k, slightly higher than the macroscopic sample, indicating that the micron crystal sample 2 had higher purity, higher crystallinity, and better copper doping.

The following, which we see in the video, proves that sample 2 can levitate at room temperature and atmospheric pressure.

Furthermore, the researchers also carried out non-ferromagnetic proof experiments on sample 2. Apart from the ferromagnetic effect, sample 2 did not respond when attracted by ferromagnets.

You can read Claude's condensed version of the summary: (for reference only)

Spanish team: LK-99 has a multi-phase heterogeneous structure, too difficult to reproduce

Experts from the Institute of Physics of the Spanish National Academy of Sciences published a paper on arXiv to conduct some research on whether LK-99 is superconducting.

They provided experimental data on superconducting Pb films and said that these data are similar to the Beihang team's observations — the relationship between resistivity and temperature is more like a semiconductor, and the magnetization strength also increases during cooling.

Paper address: https://arxiv.org/pdf/2308.01723.pdf

According to the paper, LK-99 is a heterophase structure (heterophase structure) with coexisting non-superconducting components. Depending on the specific details of the synthesis, the extent of this superconducting effect may be stronger or weaker, producing misleading results when forming the required components.

To put it bluntly, if you want to reproduce this material now, the results will be very complicated.

Because possible superconducting materials will be wrapped in non-superconducting materials, the final phenomenon is quite confusing.

Specifically, they deposited Pb films of various thicknesses on sapphire substrates under sapphire substrates.

As shown in the figure below, for thicker films, the relationship between resistivity and temperature looks like a traditional superconducting transition.

For thinner films, the curve is similar to that of a semiconductor.

Magnetic measurements have indeed confirmed that this is a real superconducting material.

Although this behavior of Pb films was obtained under different deposition conditions, it is recorded in detail in the literature. Electrons jump from one superconducting nano-island to another through macro-quantum tunneling, providing an explanation.

However, this phenomenon is a typical phenomenon of the superconductor-dielectric mass phase transition.

As a result,

It is likely a polyphase compound containing polycrystals separated by an amorphous peripheral phase or multiple amorphous phases.

However, these phases do not produce significant X-ray peaks in XRD, but they still have an effect on resistance and magnetism.

In fact, the initial ingredients

and pyrite

No molar ratio can finally form a material with a Cu/P ratio of 1/6 in a single-phase substance. More extensive edX/EBSD/edXX results are also needed to measure the content of the different phases in the product.

Indian physicist: Broad Band Mott Localization is all you need

In addition, physicist G. Baskaran from India also submitted a paper on August 2, using a title modeled after the Transformer paper to put forward a theoretical view supporting the possible superconductivity of LK-99.

Paper address: https://arxiv.org/pdf/2308.01307.pdf

In his paper, he proposed a Broad Band Mott localization theory different from the previous paper, which supports the superconductivity of the LK-99.

You can refer to Claude's explanation to aid understanding.

Furthermore, Wen Haihu, a professor at Nanjing University, previously suggested that the anti-magnetic phase transformation in the paper could easily lead to misjudgment.

According to interviews with “intellectuals,” Professor Wen said, “LK-99 is indeed “interesting” and has some unique properties.

“Currently, we are not only concerned about whether there is superconductivity, but the low resistance state at low temperature is also very interesting. And these are some of the unique properties of this material. Also, if it's not the antimagnetic effect of superconductivity, then what magnetism causes it?”

Reference materials:

https://www.yna.co.kr/view/AKR20230803057400017

https://www.nytimes.com/2023/08/03/science/lk-99-superconductor-ambient.html

https://arxiv.org/pdf/2308.01516.pdf

https://arxiv.org/pdf/2308.01723.pdf

https://arxiv.org/pdf/2308.01307.pdf

Editor/jayden