Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

Summary of events so far:<p>The claim: Room temp (~300K) superconductor exists and we got it!<p>The replication attempts: The production method is so poorly documented only a fraction of the samples being made shows any interesting properties. And among those interesting ones, results varies. Very few, if any, attempt actually completely shows the entire spectrum of properties and behaviors of a true superconductor at room temperature yet. But those kinds of experiments take time so it isn&#x27;t an indicator of problem.<p>My take: It is probably something interesting but not well understood. Best case scenario, the original sample in the Korean lab probably won the synthesis lottery and is actually a true room temp superconductor. Worst case scenario, we got another class of high temp (warmer than liquid nitrogen but cold enough that applications are limited) superconductor but nothing revolutionary since at this point, it is pretty conclusive that there is something interesting with LK-99.

For comparison, per this Wikipedia page (<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;High-temperature_superconductivity" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;High-temperature_superconducti...</a>) currently, the highest temperature, ambient pressure superconductor is around 138 K (−135 °C).<p>I&#x27;m no expert but based on my limited understanding, this result (if confirmed) while far from room temperature would still make LK99 a pretty interesting discovery in the SC world. And once a new SC like this is validated there are often methods discovered to improve the temperature or optimize other traits.<p>To me, the positive news here is that (if confirmed), at least LK99 isn&#x27;t &quot;nothing&quot;. Together with the recently released simulation studies indicating LK99 may have interesting SC-like properties, this causes me to increase my personal Bayesian SWAG estimate on LK99 (or a related descendant) eventually being a meaningful step toward room temp superconductors.

Looking at the key temperature-resistivity graphs, this feels like the data doesn&#x27;t support the conclusion that there&#x27;s a superconductor here. The temperature-resistivity graphs of superconductors I&#x27;ve seen all have a fairly steep cutoff--a sharp, vertical line at critical temperature. The log-scale here complicates my intuition, but what I see is a gradual transition into noise range. Also, the graphs I&#x27;ve seen have also demonstrated that the critical temperature varies with applied magnetic field. Here... there&#x27;s no apparent variation in apparent critical temperature.<p>I&#x27;m sorry, but this result just feels to me like people are assuming that the material must be a superconductor and are analyzing all the data under that assumption rather than asking the question &quot;is this a superconductor?&quot;

So exciting!<p>Just FYI, the wikipedia page for LK-99 has a very useful tracking grid of replication attempts with sources: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;LK-99" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;LK-99</a>

I see a lot of <i>&quot;This must be real, why would labs publish this if they don&#x27;t think it&#x27;s real, they have nothing to gain.&quot;</i> sentiment on HN lately. Or <i>&quot;Researcher&#x27;s career would be ruined if they falsely claim to replicate.&quot;</i>, and so on. I also want to believe! But I should add a bit of skepticism to the hype :)<p>- &quot;this could ruin their career&quot;: Depends. If they posted completely fake numbers or intentionally fake videos. Sure, that would be bad. But none of this is peer reviewed, and all of this can be retracted. A contaminated sample? Oops, retract. Bad measurement methodology? Oops, retract. Sure, <i>somebody</i> will remember that you made the controversial paper in the first place, but as long as you are not provably fabricating, a lot can be attributed to &quot;an honest error&quot;. There are tons of peer reviewed papers out there with errors that completely change the outcome. Does not mean the authors are &quot;finished&quot;.<p>- &quot;they have nothing to gain&quot;: Oh, they absolutely do. While &quot;science should be fully objective&quot;, funding agencies very much aren&#x27;t. Obviously, just like VC funding, science funding is not a complete coin toss. But having &quot;the right&quot; team and background is often as important as the idea itself. One way to get the right background is to &quot;touch shoulders with the giants&quot; and one way to get the right team is to be highly visible and attract talent.<p>So overall, if LK99 is <i>eventually</i> shown to be a superconductor by someone else, you have a lot to gain, even if your own initial study is not perfect.<p>Let&#x27;s say your team synthesised something. It looks like LK99 and it has <i>some</i> properties that are not really superconducting but at least a bit unusual. This clearly isn&#x27;t what you hoped for. Now, do you run a bunch of other controls to see if it is some form of contamination, process error, combination of both... or do you publish a vague click-bait paper on ArXiv and hope that other results will somewhat align with yours?<p>Finally, I&#x27;m not claiming this paper or any other paper intentionally published untrue or misleading results. Just that scientists are also people. They have FOMO, they follow trends, they see what they want to see. As always, big claims require big evidence, and so far we don&#x27;t really have that. But that does not mean there isn&#x27;t some truth to the big claims :)

I&#x27;m puzzled by this, looking at the resistance versus temperature graph they&#x27;re not demonstrating zero resistance at 110K, they&#x27;re demonstrating that at 110K the resistance becomes so low that it reaches the noise floor of their instrument. It&#x27;s a stretch to call that superconductivity because when it come to that it needs to be actually zero, as in &quot;I can put a current in a loop made of the material and come back one year later and it will still be there&quot;. Exponential decay will quickly catch up with a non-zero value, even very very small. Still this exponentially decreasing resistivity looks interesting, I have no idea if that&#x27;s unusual or if that means anything. The weird dip at around 230K will need to be explained as well. I&#x27;m just an interested bystander, that goes without saying.

This is <i>so</i> reminiscent of what happened after Fleischmann &amp; Pons. Labs attempting to replicate saw this property, or that property, but never the whole, unequivocal picture.<p>Here we have a room temperature superconductor that isn&#x27;t a superconductor at room temperature. A sample that has no measured Meissner Effect at any temperature. And the authors admit that some (many?) of the samples tested out as semiconductors.<p>Also, they don&#x27;t happen to mention how they measured resistance. 1mA current, yes, but what equipment? And what setup? Micro-measurement of resistance is <i>hard</i>. We really need to know more about that.

I&#x27;m very much conservative about this paper because while the graph in Fig. 3a says $T_c^{zero}$ being 110 K, the &quot;zero&quot; resistance is actually only 1e-5 Ω (!) and even if the sample is possibly superconducting its critical temperature would be much lower than 110 K anyway. I&#x27;m aware of the difficulty in obtaining larger samples, but the label in that graph is really misleading regardless.

I don’t understand the physics, but it <i>feels</i> like a truly zero resistance conductor would violate some law of thermodynamics or something.<p>Is a superconductor truly zero impedence or just very very very low? Because I’m seeing a lot of these graphs with something like: “0.00001ohm” as the y-axis floor.

Worth noting that the sample used did not produce a Meissner effect, but was still superconductive at ~100K.<p>&gt; To further verify the superconducting properties, we conducted magnetic measurements on the sample, but unfortunately, no obvious Meissner signal was observed, indicating that the superconducting volume fraction of the sample may be very small. The preparation of high-purity samples are still a challenging task.

Question for the cognoscenti: supposing that LK-99 superconducts with T_c = 110 K, how significant a discovery would this be? I.e., does it establish a brand new class of high-T superconductors, or is it merely one unremarkable member of a known class? Further, does it offer advantages over other high-T superconductors such as ease of fabrication or cost?

Isn&#x27;t it a faux pas to put the degrees-symbol after the unit K?

Pretty cool! The question is how cool?

Can someone point me to a list of exciting applications of room temperature superconductors? Trying to understand why such excitement about this!

Here&#x27;s Brian Keating interviewing Jorge Hirsch from UC San Diego and Inna Vishik of UC Davis [0]. Prof Hirsch was&#x2F;is a leading critic of the U Rochester papers, but thinks that LK-99 could work.<p>[0] <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=qQnDatnAWP4">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=qQnDatnAWP4</a>

It’s real, it works, the Navy has a linked patent from 2017.<p>The UFOs are a PSYOP.

And now for a slightly different take on the much-discussed room temp. superconductors:<p>on the off chance that this LK-99 stuff is actually going to be a thing, how should that influence my investment portfolio over the course of the next five years?<p>Should I buy lead mining stock ?(joke, obviously, but you get the point).

&gt; In conclusion, we successfully synthesized the compound Pb10-xCux(PO4)6O, and observed the zero resistance above 100 K. However, the Meissner effect has not been observed yet in our samples, which suggests that the superconducting volume is relatively low.<p>In conclusion, ... nothing?

Note that there is no signs of phase transition (no jump) and the values below 110K are around reasonable measurement resolution. It may be that they just got the resolution threshold and misinterpret it as SC

- it’s an easy to make room temperature superconductor!<p>- ok it’s hard to make but still RTSC!<p>- ok it’s superconducting at 100K but its a novel class of SC! &lt;= <i>you are here</i><p>- ok it’s not a superconductor but it still has interesting properties!<p>- ok it doesn’t have singular properties but it could have!<p>I predict there will still be LK99 truthers in 20 years arguing that this amazing discovery was buried by big copper conspiracy.

Encouraging evidence that the recent work on room temperature superconductivity might be real!<p>Still waiting for confirmation from multiple labs.

As a lay person not graduated in STEM subjects, can someone ELIFY how is this research useful to society?

The most compelling evidence offered thus far is from actual scientists that have reviewed the LK-99 paper and determined the scientists involved aren&#x27;t very good at science.

In the observations, this sample they tested did not exhibit the Meissner effect at room temperature. Which means it’s not the same thing the original team discovered?

ELI5, if these folks confirmed zero resistance at room temp and atmospheric pressure, isn&#x27;t that confirmation of the original paper?<p>Edit: I read 100 K as 100°c. Mea culpa.

Could someone explain why this is important? What is the consequence of the existence of Superconductors like that?

I really really wanted this to be true just so we can all take a look at how much wrong some things are in academia and science nowadays.<p>Plenty of &quot;knowledgeable&quot; people and research groups put out a lot of discrediting (and actually ignorant) statements about this, a lot of them with a dash of xenophobia in the mix.<p>Congrats to the people that actually push science forwards!<p>Haters gonna hate but no one will remmeber them, ever.

I see lead (Pb...something) as main ingredient, isn&#x27;t it banned in most industries because how toxic it is and how hard it&#x27;s to handle in industrial scale? isn&#x27;t that a problem for potential mass applications?<p>(lots of comments about this discovery call this revolution that will change everything around us and that somehow implies mass production I guess)

I&#x27;m impressed that Pb₁₀₋ₓCuₓ(PO₄)₆O is completely representable in Unicode.

Reliable production of the material is an engineering problem. If it can just be shown to work once, then the goal will be to mass-produce it in useful forms and structures.<p>Replication has been partially successful, exhibiting remarkable new results that are already worth celebrating.

So this almost means the holy grail has been found or we are pretty close?

Why is western mass media silent? They always pick up emerging stories like that, but not in this case for some reason

I wish we had real money prediction markets. Afaict it would be legal to run such a business in the UK.

Off-topic, but I admire the effort to translate the formula to Unicode characters in the title. It&#x27;s not just a simple copy-paste from the article.

LK-99 contains polonium? which has a half-life of hundred and something days.

A 110k superconductor would not be revolutionary since we already have some in that vicinity.

Is this one also written in Word so it automatically loses LaTeX-credibility, as was commented under the first paper? (:

I completely ignored the authors (as I usually do) and started reading it, noticed the slightly odd phrasing, and then chuckled at &quot;mad great efforts&quot; and then &quot;a very excited news&quot; a short while later before looking at the authors and realising the country of origin.