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Hello everyone.

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I am Sun Yueyue from the Department of Physics at Southeast University.

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Today I will report to you on the latest research results of our group on LK99.

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Recently, the topic of extraterrestrial superconductivity has been very hot.

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We have seen many reports on this.

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As researchers in the field of superconductivity, we are very happy.

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We have received a lot of interest in our work.

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However, we have also noticed that some media or self-media outlets have been over-reporting or distorting our experimental results.

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Therefore, I would like to take this opportunity to introduce our findings to you through this video.

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Our work has already been published in the journal Accounts, so you will soon be able to read the full article.

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First of all, let me clarify the most important point.

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We have neither confirmed nor discovered extraterrestrial superconductivity.

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However, we have successfully observed zero resistance below 110K.

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This could be an important piece of evidence for the existence of superconductivity in this material.

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Now, let's take a look at the paper and provide you with a detailed explanation.

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Let me first introduce our research team at the School of Physics, Southeast University.

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This work was mainly carried out by three students: Hou Qiang, Wei Wei, and Zhou Xing.

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Professor Shi Yang and I also contributed to this work.

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Now, let's directly examine the figures in our paper and explain them to you.

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The first figure shows our X-ray diffraction results.

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On the left are the XRD results of two precursor materials.

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On the right are the XRD results of the materials we synthesized.

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We conducted X-ray diffraction on four batches of samples.

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We compared our X-ray results with those reported by a team from South Korea.

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The X-ray patterns of our samples match very well with the reported ones.

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In fact, our samples are even purer than theirs.

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The peak corresponding to impurities in their samples is much smaller in ours.

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Therefore, we can say that our samples have a higher level of purity.

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Now, let's move on to the most important part - the zero resistance results.

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Let's take a closer look at our measurements.

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We started measuring from 300K and gradually decreased the temperature.

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The current passing through the sample was one milliampere.

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Due to the fragility of the sample, it was difficult to shape it into a regular form.

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Therefore, we used an irregularly shaped sample to save time.

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We measured the resistivity using the four-probe method.

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Under a current of one milliampere, we observed that the resistivity exhibited slight semiconductor behavior at high temperatures.

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As the temperature decreased, the resistivity decreased as well.

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The most crucial observation was made at 110K.

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At this temperature, we observed that the resistance approached zero.

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Why do we say it approached zero?

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If you look at the scale of the resistance on this side, it is around 10^-5 to 10^-6 ohms.

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Considering the current of one milliampere, the corresponding voltage is around 10^-8 or 10^-9 volts.

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This is within the measurement range of our instrument, PBMS.

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Therefore, we believe that we have observed zero resistance.

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This is our sample.

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In our previous experiments, we observed a strange drop in resistance at around 250K.

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The cause of this drop is still unknown.

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It may be due to some impurities or other factors in the measurement setup.

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We are still investigating this phenomenon.

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We also conducted measurements of the superconducting transition under a magnetic field.

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We observed that the superconducting transition remained relatively stable under the applied magnetic field.

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The critical temperature, TC0, showed only a slight variation.

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However, there were some peculiarities in the superconducting transition under different magnetic fields.

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For example, at low fields such as 0 Tesla and 135 Tesla, the superconducting transition shifted to lower temperatures as the magnetic field increased.

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However, at 9 Tesla and 7 Tesla, the superconducting transition seemed to revert back.

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The reason for this behavior is still unknown.

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Finally, I would like to mention that we first observed a sharp drop in resistivity similar to a superconducting transition on the afternoon of August 1st.

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However, at that time, the resistivity did not reach zero and had a small value.

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Therefore, we intensified our sample selection process.

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We tested a total of six samples, but we only observed zero resistance in one of them.

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In most of the other samples, we observed behavior characteristic of semiconductors.

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In addition, we performed measurements of the Meissner effect on the sample with zero resistance.

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However, we did not observe complete diamagnetism in the magnetic measurements.

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Therefore, we speculate that if the zero resistance in our sample is caused by superconductivity, its superconducting component is relatively low.

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This concludes the main findings of our work.

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I would like to express my sincere gratitude to the three students who worked diligently on this project.

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I would also like to reiterate the most important points.

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We have successfully observed zero resistance below 110K in the LK99 material.

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However, this does not constitute evidence of room temperature superconductivity.

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Further exploration and measurements are needed to determine if room temperature superconductivity exists.

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Our team will continue to make efforts in this direction.

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We hope to bring you better results in the future.

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Thank you, everyone.