Last month, Chinese researchers published a pre-print article where they found Possible Meissner effect near room temperature in copper-substituted lead apatite. This was an Lk99 variant with sulfur in the chemistry. They detected evidence of possible Meissner effect magnetic fields which would be consistent with room temperature superconductivity.
The lead researcher, Yao Yao, is sending out messages that more experimental evidence consistent with room temperature superconductivity is being found. It is still not conclusive and has not been published.
Professor Yao Yao said that the LK99-like samples from the research group at Central South University reached the milliohm level in the multimeter resistance test! pic.twitter.com/ugleifGHJl
— peoplewar2 (@REDLFLAG) February 7, 2024
Professor Yao Yao said that he was forced to change the raw material because of the lack of cuprous phosphide, and unexpectedly achieved very good results. pic.twitter.com/hoKPwTntvZ
— peoplewar2 (@REDLFLAG) February 7, 2024
Prof Yao Yao said the conductivity of the samples in the latest full levitation video is too good and the microwave absorption is super strong, which is similar to YBCO superconductors, and the resistance detection takes a while. pic.twitter.com/o3q4McKeOQ
— peoplewar2 (@REDLFLAG) January 26, 2024
https://t.co/9y9t6Wnh3z
Yao Yao, a professor at South China University of Technology, published a summary article describing new discoveries in the research of LK99-like materials, problems in the synthesis and testing process. pic.twitter.com/7l1NQEesnd
— peoplewar2 (@REDLFLAG) January 19, 2024
China Internet Discussion of the LK99 Related Work
China Internet Discussion of the LK99 Related Work
Summary of the stages of copper-substituted lead apatite research
This time, room temperature superconductivity is the first truly cross-professional collaborative scientific research model. Alchemists encounter many complex phenomena and do not make professional and confident judgments, and may miss a lot of valuable information. So I wanted to write a nanny-level summary article about copper-substituted lead apatite (CSLA) for a long time, but I never got around to it. I finally have some free time after the holidays these days, so I will recall every bit of the past few months to prevent myself from forgetting. Apart from Koreans, I should be the person who has seen the most experimental and theoretical data so far.
Question 1: Why is it one-dimensional?
Let’s start with this question from teacher Li Xiaoquan. This is also the starting point of the whole story.
If you asked me whether Korean articles were rough at the beginning, I would answer that they were very rough. So why did I read this article from the standpoint of superconductivity in the first place? Is it because Teacher Li Xiaoquan said that I never do experiments? There is indeed a saying in the physics world: Experiment means that no one else believes it except yourself; theory means that no one else believes it except yourself.
But what I believe in is precisely the theory. When I look at experiments, I always look at them with the corresponding theoretical basis. I cannot look at experiments without theory. For example, for the same ferromagnetism, what ordinary people see is that this phenomenon seems a bit similar to the magnets they played with when they were children. Professionals must ask, lead, phosphorus, copper, oxygen, and at most sulfur. Where does ferromagnetism come from?
At the beginning, everyone got the same information. But out of theoretical intuition, the first thing I noticed was the one-dimensional feature of the apatite structure itself. It entered my thinking level before the bad experimental data, so I showed something different from “fake at first sight”. manner. Because this one-dimensional structure makes me believe that the experimenter is looking for the target material in a targeted manner, rather than blindly trial and error. If it is the latter, it will reduce its credibility.
Here we need to clearly define what “one dimension” is. Everyone has also noticed various videos. No matter Oxbridge, Lovely or Ton, the samples are all in the form of long strips. It can also be seen from the electron microscope photos of lighters. This one-dimensional rod-like structure is lead-phosphorus. Greystone intrinsic. But the one-dimensional thing I’m talking about here is at the microscopic level, not exactly the form of a crystal.
There are numerous materials with apatite structure in nature. They have been widely studied in fields such as molecular magnets, but have not shown superior performance than other structures. So it’s not just a one-dimensional channel that can superconduct, it also requires a special element, copper.
When I saw the idea of stuffing copper oxide into that one-dimensional channel, my first reaction was “interesting.” I have always only used these three words when looking for research topics for myself, and I have rarely come across any topics that follow the trend and are easy to publish in top publications. For me, no matter what happens in the end, this journey of exploration will definitely be worth the price of admission, so what are you waiting for? There are not many interesting topics, and I don’t think those who are sarcastic are necessarily working on more interesting topics than this one.
What kind of one dimension the “one dimension” here is, I haven’t completely thought about it until today. We used a quasi-one-dimensional ladder model in the article, which is more in line with the diagram drawn by the Koreans. But in fact, it is not necessary to use a ladder. Real one-dimensional specifications can also be considered. The more popular disorder-free localization is such a model. This problem can be left to be solved later.
The so-called one-dimensional is nothing more than limited dimensions in two directions. As long as this condition exists, it will definitely bring about brand-new physics. Needless to say, typical one-dimensional systems such as polymers and DNA, semiconductor nanowires, carbon nanotubes, etc. also produce rich physics.
Question 2: Fully suspended or semi-suspended?
Mr. Guan’s semi-levitation is undoubtedly the most out-of-the-box scientific research practice in history. People saw a brand new future just like Oster saw the small magnetic needle shaking. Although Magneto always said that these phenomena could be simulated by using pyrolytic graphite and ferromagnetic powder, as the alchemists came up with all kinds of weird video display methods, Magneto became increasingly unable to resist.
To simulate diamagnetism, only pyrolytic graphite can be used. However, graphite is light and has weak diamagnetic properties, so even a little bit of magnetic powder on it will not carry it away. The application of magnetic powder is also very particular. If it is applied to the middle, it will not show a semi-suspended look. If it is applied to the edges, it will not bounce out. It becomes an exhausting chasing game.
From Mr. Guan, to Oxbridge scum, to Cutie, to Dandelion City, and then to Brother Ton, you will find that the samples independently made by all of them have exactly the same behavioral rules, semi-levitation, single-point levitation, and so on. Refusal to leave, stay, etc. is a highly repeatable phenomenon. Magneto also admitted that as long as the position of his magnetic powder is different, the floating point will be different. In other words, using pyrolytic graphite plus ferromagnetic powder cannot simulate uniform behavior and is highly dependent on the structural distribution of the sample. However, you can never assume that all the samples of the above-mentioned people have a small iron bead at the tip of the sample, right?
So I have always deeply suspected that one-dimensional superconductors can only be semi-suspended, and cannot be fully suspended like two-dimensional copper oxides. This is because there is spin charge separation in one dimension. When it is in the spin or vortex liquid phase, it is very difficult to It may be gathered towards one end under the influence of magnetic field. So most videos show this phenomenon. The sample has no magnetic response for a short period of time, but after the magnet acts for a while, a sharp corner will suddenly be sucked up, as if it is magnetized.
As we all know, under the action of a strong electric field, a conductor will exhibit tip discharge. I think the current phenomenon of magnetic vortices gathering toward the tip is similar to this. Friends who are interested can build an electromagnetic model and calculate it.
In fact, if you carefully observe the levitation of YBCO, it always has a sharp corner facing the magnet, which is not a random direction. Lao Qiao did an experiment. He used a long strip of YBCO to float, and one end almost stuck to the magnet. The shape was very similar to the semi-levitation. However, the background antimagnetic properties of YBCO blocks are strong enough, so they can float. At present, the diamagnetism of CSLA samples is still too weak, so there will always be some contact points, even if the contact point of Oxbridge slag is only micron level.
Question 3: Where does the copper sulfide oolong come from?
As we all know, the most famous couple in the ore industry is copper and sulfur. Copper is the number one sulfur-loving element, and sulfur is also the number-one chalcophile element. Among the few minerals in nature that do not contain oxides as the main mineral, copper is the most famous.
Because the raw materials for firing CSLA are pyrite and cuprous phosphide, they all thought that the phosphorus replaced the sulfur, but Boss Dai immediately noticed that it was the copper that combined with the sulfur and took it away from the lead. Therefore, the presence of copper sulfide in CSLA is not surprising, but it is a bit incomprehensible to directly talk about copper sulfide.
Apatite is a typical ionic compound, and copper is an inactive metal. I have never seen anyone put copper into apatite. So from the beginning, the key to this problem was how to get copper into the crystal lattice. Mapp calculated that it would not work, because the base was too high. Teacher Chen also calculated that it would be fine, just use sulfur to lower the energy barrier.
This is chemical literacy. If the barrier is too high and there are no moves, then the materials currently available to humans will be one or two orders of magnitude less. There are so many chemical substances that cannot be synthesized in theory, but not all of them have been solved one by one in the end.
I don’t know why the public is so tolerant of the Max Planck Institute. Mr. Dai later told me that anyone with a little knowledge of XRD could tell that he didn’t even get lead apatite in his structure, but used lead phosphate to fool him, and the lattice constants were all wrong. At that time, I sent a party to the party and said that I would wait for the Max Planck Institute article to come out to see how I could quibble. Now I want to say that the institute has a great brand, so it can really be said that a deer is a horse.
Among the elements, copper should be the second most complex element after carbon. It stands to reason that copper, like silver, should have the most stable price, which means throwing away the 4s electrons in the outermost layer. But it is easy to lose one of copper’s 3d electrons, and an unpaired d electron will appear, which is what I often call a free radical. Monovalent copper has no spin magnetic moment, while divalent copper contributes a magnetic moment due to the presence of lone pairs of electrons. The copper oxide high-temperature superconductor has an alternating structure of one layer of one valence and one layer of two valences. I said from the beginning that this fractional valence is the most attractive property.
Traditional high-temperature superconductors mainly adjust this valence state through doping. But in CSLA, we now believe that it is adjusted through the price changes of these elements. In particular, the sulfate radical becomes elemental sulfur or an anion, gaining a large number of electrons, and some of the lead may also change in price. Some of the electrons are donated by phosphorus from anion to phosphate, and some are taken away from copper. This ratio is currently difficult to control, and is one of the reasons why the synthesis process has always been difficult to stabilize. In addition, it is still unknown whether other elements that may participate, such as carbon, silicon, iron, etc., will contribute. For example, Brother Ton’s sample may contain graphite, which needs further study.
The study of copper-substituted lead apatite can be said to be the first step in the study of complex and strongly correlated systems. There are too many problems that need to be solved, and we are only just getting started.
Question 4: What is ferromagnetism?
The combination of non-magnetic elements such as lead, phosphorus, copper and oxygen creates ferromagnetism, which is an extraordinary thing in itself. Therefore, many scholars initially said that iron was inevitably mixed into the raw materials.
I repeatedly told the scumbag to avoid any iron-containing substances in any part of the magnetic test. After several rounds of experiments, the iron content has long been reduced to a level that even low-temperature EPR cannot detect. Of course, the possibility of other ferromagnetic elements is even smaller. EPR is very sensitive to magnetic elements, and the peak positions of most magnetic elements have been calibrated. The occurrence of characteristic peaks can be seen immediately, so it can be ensured that it will not be interfered by magnetic elements.
Under this circumstance, we still synthesized many ferromagnetic samples, including many in Kaidaita. This is very puzzling. But if you look carefully at these magnetic curves, there are still differences. Some of them should actually be classified as antiferromagnetic or spin glass.
A little nanny-level science for alchemists. When you measure the MH curve, if you see a straight line passing through the origin in one or three quadrants, it is paramagnetic; if it almost passes the origin and becomes saturated at high fields, it is soft ferromagnetism; however, the origin is different. A very open hysteresis loop, this is a hard ferromagnet; it passes the origin, but changes more drastically at low fields, slowly increases at high fields, and is not saturated, which is likely to be antiferromagnetism; it saturates for a while, and then suddenly increases , forming multiple steps, which are likely to be ferrimagnetic, and antiferromagnetism can be regarded as a special case of ferrimagnetism. To see the spin glass, you also need to lower it to a lower temperature to measure MT to see if it will drop sharply.
Putting aside superconductivity, CSLA has almost never experienced hard ferromagnetism or ferrimagnetism. The most common ones are soft ferromagnetic, followed by antiferromagnetic. Alchemists should be aware of these two situations. The former occurs when copper is excessively doped, and the latter occurs when copper is severely underdoped. If the latter further increases the doping amount, diamagnetism will appear, and Meissner can be measured. This is consistent with traditional high-temperature superconductivity.
In short, whether it is measuring EPR or SQUID, in fact, by scratching the NdFeB a few times, an experienced alchemist can basically determine which phase it has been synthesized into, which is very effective for rapid screening. Throw the whiteboard away as soon as you encounter it. Don’t waste time like Oak Ridge did. When doing this research, you must make full use of the characteristics of room temperature, and you can’t just run to measure 2K for everything, as one comment said, that is just a waste of time.
Question 5: Why not measure zero resistance at the beginning?
Most modern physical experiments are based on spectroscopy experiments, because spectroscopy has features, and a characteristic peak is clear and cannot be questioned. The traditional transport test IV curve lacks features. If you say it is small, it is considered small no matter how small it is. This is a vague concept that is difficult to define. Therefore, to determine the physical and chemical properties of a material, it is most reasonable to do spectroscopy first.
Even if transport is to be measured, spectroscopy methods such as differential conductance should be given priority and the zero-energy mode should be determined first. This is an ideal situation. Of course, there are other spectroscopic methods available, which we are currently working on.
The Koreans came up with a very clever idea, using copper substrates for controlled experiments. I remember that very early on I said that there was copper underneath, and I was ridiculed in various ways, saying how could it be possible to use metal as a substrate. Now it has been confirmed what I thought at the time. The hero sees the same thing. It is essentially problem-oriented. When encountering difficulties in actual measurement, you will think of solutions. The scoffers are just standing by with textbooks and saying you are wrong because you don’t have to work.
Transport is a much more complex subject than magnetism. After all, magnetism still has the paramagnetic Curie-Weiss law as the basis. Even the most basic Ohm’s law has an extremely limited scope of application. The critical current of superconducting is usually only used as the derivation of the critical magnetic field. Even zero resistance is often derived using Meissner, so Meissner’s priority is higher than zero resistance at all times.
I have always said that the four-electrode method, or the Vanderbilt method, is problematic on this sample. Inhomogeneous samples, strong local memory effects (inductive reactance), and possibly strong boundary effects will limit the effectiveness of this method.
We who make organic semiconductors all have this experience. If the molecular material coating film is unevenly applied, strange transport properties can be measured. Transport is a multi-level phenomenon, involving both the microscopic molecular level and the macroscopic device level. The quality of the film, the quality of the electrode, the surface interface, etc. all have a significant impact. The result of transport is not necessarily intrinsic to the material. , sometimes it’s just that the sample is not ready. This is also the reason why I am reluctant to do transportation first. I always hope to understand the properties of the material itself thoroughly before doing macro tests.
The essence of microwave absorption is also transport. I learned about alternating current in middle school. Regardless of spin, low-field microwave absorption will occur only if there is superconducting current in the material. This has been said a long time ago. Therefore, with LFMA as a base, there is no rush to do macro transport. It is just a repeated verification.
Question 6: How to make it bigger and how to purify it?
The phase diagram has actually been mentioned before. Underdoping of copper means that it has good diamagnetic properties and is prone to Meissner. Overdoping of copper means that it has many carriers and is prone to zero resistance. The ultimate goal is to find a middle point where both Meissner and zero resistance appear at the same time. If it is under-doped, try to add as much copper as possible, and if it is over-doped, try to reduce the proportion of copper. You will definitely be able to find the optimal point.
What is more difficult to determine now is where copper should be better. Koreans talk about the outer circle, but Dai always talks about the inner circle. It is true that the inner circle is more difficult to enter, and the active layer is also in the inner circle. The way that the stupid boss uses sulfur to guide is very interesting, and the way that the scumbag uses to adjust his price is no less impressive. Alchemists each have their own merits. Black cats and white cats can achieve good results.
Regardless of water method or fire method, there is nothing special about the craft itself, and there is no principled difficulty in making this step bigger. In order to test the conditions, each batch of raw materials was divided very finely and different parameters were set, so the amount of each sample was relatively small. When the process matures, just burn the same set of parameters.
Now it is mainly because there are few people participating and each alchemist has to be responsible for a lot of content. If there are as many practitioners as graphene and perovskite, and enough manpower can be allocated to each process, the firing efficiency will only increase faster. Of course, this is something that happens after it is actually done.
We are far from reaching the bottleneck period yet. There are still many parameters that can be optimized. The only constraint is time.
Question 7: What other trump cards do I have hidden?
I don’t have any trump cards, they’re all just a foil. We started to enter the forest at the end of August and published the second paper at the end of December. At this stage when everyone thought the matter was over, we quietly conducted experiments for four months. Dozens of samples, thousands of loops, this is the trump card.
During this process, we have measured YBCO, ferric oxide, and many rare ferromagnetic elements that we had never thought of before, and we have made up for them in these four months. After countless excitements and collapses, I was able to serve up such a bland dish.
If you ask whether we have hidden anything, we must have hidden a lot. The formula has not been fully disclosed, and the key processes of the process have not been written down. This is the case for scumbags, and the same is true for idiot bosses. If you say that if you don’t make it public, how can it be repeated? I can only say that if it is fake at first glance, how can it be repeated?
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
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