Great Country Academician

Along with Xu Chuan's two papers on arxiv, the discussion on KL-66 materials once again set off a wave on the Internet.

But this is almost the last flashback.

After all, the magnetic levitation mechanism of KL-66 has been explained accordingly. Unless a subsequent research team can observe the Meissner effect on the reproduced KL-66 material, it is basically impossible to make another turning point.

In the next few days, the re-engraving results announced by various scientific research teams in various countries can be regarded as fully confirming that LK-66 is not a superconductor.

Even South Korea's own scientific research institution, the South Korean Society for Superconductivity and Low Temperatures, publicly released the news that "there is no result to prove that the KL-66 material has superconductivity".

Although it is a pity that a new path has not been found in the field of materials, this is not the first time such news has appeared in the field of room temperature superconductivity.

Xu Chuan did not turn around in the news from the accident world. He has already returned to Nantah University and is doing deduction and research in his office.

Although it has been confirmed that KL-66 is not a room-temperature superconductor through calculations and replica experiments, his research on it is not a waste of time.

Instead, in this diamagnetic material, he discovered a novel atomic doping structure.

The inversion-asymmetric spin-orbit coupling of Cu atoms has a significant impact on the band structure and electronic properties of the material. The core lies in the fact that the two branches of the Fermi arc state electrons connect the c-axis and break the inversion symmetry.

This in turn leads to the splitting of the Dirac cone into two Weyl nodes with opposite chiralities, leading to nontrivial quantum phenomena.

This is the core mechanism of KL-66 material showing strong diamagnetism and even floating in a strong magnetic field.

It is also a phenomenon that has never been discovered in the field of physics and materials science.

What he explored was also the secret behind this phenomenon.

"Professor, you are back."

In the office, Cai Peng walked in, saw Xu Chuan sitting behind the desk at a glance, and shouted in surprise.

If you ask a question on β: "What kind of experience is it like for a mentor to be a top-notch expert at the level of a Nobel Prize winner?"

He Cai Peng is definitely qualified to answer!

First of all, it is certain that it is good to learn from such a top expert.

However, it is often disappointing that mentors of this level are basically not in the office most of the time, either participating in national projects or busy with their own things.

Just like him, he has been with his mentor for more than two years, and he has met his mentor, which can be said to be one of the few.

For students, most of the time, they are like left-behind children, learning everything depends on self-consciousness or looking for senior brothers and sisters.

If the tutor you meet has high requirements for graduation, it will be even worse.

Fortunately, he also has a senior brother, Gu Bing, who has graduated and left, but is still a professor of mathematics at Nantah University.

When encountering some problems, he can still ask this elder brother for help.

But relatively speaking, he studied differential equations, while Gu Bing studied algebraic topology and analytic geometry. Many times it is impossible to guide him.

In this case, all he could do was send the question to Xu Chuan through prestige or email.

Although they can basically receive answers, the efficiency of asking questions through these methods is definitely much worse than face-to-face questions.

Of course, he can also understand this situation, after all, his mentor is a bit too 'beta'.

But understanding is understanding, but he doesn't see anyone all the year round, he is always like a left-behind child, and he is also suffering.

Hearing the voice, Xu Chuan looked up, nodded with a smile, and asked, "How did you go about the question I gave you earlier?"

When he came back last time, he wrote a question to this student to check his skills in the past two years, so as to make a targeted course arrangement for him in the future.

However, it was delayed for a while because of the KL-66 materials in South Korea. The three days mentioned at the beginning must have passed.

Cai Peng nodded, walked quickly to his place, found the manuscript paper from the drawer, handed it to Xu Chuan respectfully, and said: "The top stack is the thoughts of the previous three days, and the bottom part is the papers I wrote these days. some ideas."

In fact, more than ten days have passed since I got this question.

He also studied the problem on the manuscript paper for more than ten days, but he couldn't solve it, but there must still be some thoughts and thoughts.

Xu Chuan nodded, reached out to take the manuscript paper, and began to read it carefully.

"The foundation is not bad, and there has been some progress in the past two years." After reading the answer sheet, Xu Chuan said with a smile: "However, you have taken a lot of detours in some aspects."

Then, he got up and dragged out a blackboard from the corner of the office, and pointed while writing: "For example, when solving this module, you used the Gaussian elimination method to make the augmented matrix (A|b) an elementary Row transformation, transformed into a ladder-shaped matrix and then processed."

"This way is correct, but don't you think it's a bit too complicated?"

Looking at the calculation formula on the blackboard, Cai Peng scratched his head and said, "Is it okay? I think the Gaussian elimination method should be very suitable for this application."

Xu Chuan smiled and said, "Then do you remember iteration?"

Cai Peng thought for a while, his eyes suddenly brightened, and he blurted out: "Gauss-Seidel iteration!"

Xu Chuan nodded with a smile, and said: "That's right, when the coefficient matrix A is strictly diagonally dominant or symmetrically positive definite, the Gauss-Seidel iteration must converge. Starting from this aspect, it will be faster than the Gaussian elimination method you use. Easier."

After a slight pause, he continued: "Solving linear algebraic equations is one of the most basic problems in scientific and engineering computing. Most of the computing problems ultimately come down to the solution of linear algebraic equations."

"The main difficulty in solving large-scale linear equations lies in the workload. How to reduce the workload is the key you should think about."

"Of course, there is also my dereliction of duty here. I really didn't teach you anything in the past two years. But I should be in the office for the next few months, so I can teach you well."

In the office, in response to Cai Peng's answer sheet, Xu Chuan picked out some questions and taught them.

It may be due to his own experience, no matter in his previous life or in this life, he has learned a lot by himself. Therefore, for the few students he brought, he also tended to be a stocker.

But this approach is not for everyone. And even if it is stocking, it is still necessary to teach some core theories and ways of thinking, otherwise sooner or later it will go astray or fail to understand the core.

After half an hour passed, Xu Chuan stopped and said, "Let's come here first today. You should absorb and digest the things I said in these two days."

"In addition, I will list a few books. You should read them carefully in the past two months. In some knowledge points, you still lack a lot and need to learn."

While talking, he erased the formulas on the blackboard, thought for a while and wrote: "Elementary Differential Equations and Boundary Value Problems", "Theory of Special Functions", "Numerical Solutions of Differential Equations", "Mathematical Methods for Physics and Engineering", "."

After listing six or seven books, he threw the chalk in his hand into the chalk box, clapped his hands, and said, "That's all for now. I'll give you three months to study. If you have any questions in the middle, you can ask me anytime." Me, I will test your learning results in three months."

Looking at the six books neatly listed on the blackboard, Cai Peng couldn't help but swallowed dryly.

Six books, three months, an average of two books a month!

boss! This is not an online novel, but a mathematics textbook!

Suddenly, he remembered a sentence that Senior Brother Gu Bing had said to him before: "Learning from the instructor, bursting the liver is a must-have skill!"

On the first day when the instructor came back to teach him, he realized what it means to explode the liver is a necessary skill.

After letting Cai Peng go to school by himself, Xu Chuan sat back at his desk again.

Restart thinking about the possibility of a complete correlation between strong diamagnetic materials and energy band topology.

The problem of strongly correlated electron systems is one of the core issues in condensed matter physics.

In materials such as complex transition metal oxides (TMOs), due to the strong electron-phonon or electron-electron coupling, the collective behavior of system electrons determines its macroscopic properties, while the simple superposition of the kinetic energy of individual electrons no longer plays a dominant role.

With the change of external conditions such as temperature and magnetic field, various order parameters such as the lattice structure, electronic structure and spin arrangement of the material will be entangled with each other, resulting in an extremely rich phase diagram structure.

Furthermore, it shows macroscopic quantum phenomena such as high-temperature superconductivity and giant magnetoresistance, endowing materials with new properties with great application value.

Undoubtedly, this new phenomenon discovered on the KL-66 material belongs to the strong electron correlation system.

But it is quite troublesome to integrate this system with mathematical language and explain it.

After thinking for a while, Xu Chuan took out a stack of manuscript paper from the drawer.

【Research on correlation effect and superconductivity in multi-orbital strongly correlated system】

"S = (kB/e)ln(ge/gh)"

As soon as he wrote a title, before he could develop it further, someone knocked on the door of the office.

"Please come in." Xu Chuan responded, and it was Tan Shaoyuan, the new president of Nantah University, who came to look for him.

"Academician Xu, regarding what you said about recruiting students last time, I have already had someone do a preliminary screening here. The list is here, take a look."

After Tan Shaoyuan greeted with a smile, he handed over the list materials in his hand.

Xu Chuan took the list and said with a smile: "Thank you, but for this kind of thing, just arrange for an assistant or secretary to come over. I would also like to ask the principal to send it over in person."

Tan Shaoyuan smiled and said, "Stop by the way, what's the trouble?"

After a slight pause, he continued: "This time, besides the list, there is one more thing I want to ask."

"Well, please tell me."

Tan Shaoyuan coughed lightly, and said: "Academician Xu, when you were teaching last time, you said that you were going to open a course on computational materials science at Nanjing University. I want to ask about this."

A Nobel Prize winner, and also the scholar in front of him who is known as the father of controllable nuclear fusion, the courses offered by this top-notch expert will be greatly affected no matter which country or university they are placed in. Welcome to attract countless talents.

Apart from these, for schools with this course, it is definitely a matter of properly expanding the school's academic atmosphere and international reputation.

Therefore, more than ten days ago, after Xu Chuan finished that class, he came to the door with concern.

However, at that time Xu Chuan had already left Nantah University and went to the Chuanhai Material Research Institute to do experiments, and he didn't come back until today. But this time, he couldn't wait to find him, wanting to ask about the situation.

In today's academia, the position of the leader of the University of Nantah is a very popular position.

After all, there is the number one person in the academic world in Huaguo and even the whole world. As long as this person is still in Nantah University, he can make various achievements in a few years.

Hearing this question, Xu Chuan suddenly remembered what he said in class before.

Smiling, he said, "I had this idea before. After all, I still have some understanding in the field of computational materials science. I want to see if it can be spread."

Hearing this, Tan Shaoyuan quickly said: "Then I will make arrangements here and do the relevant work as soon as possible."

Xu Chuan said with a smile: "There is no need to worry about this. Although I have ideas in this regard, my time here is not stable. If I specialize in a subject, I am worried that I will miss the students who apply for this subject."

After thinking for a while, he said again: "Well, don't treat the course of computing materials and mathematics that I'm teaching as a major and a minor. Let's open a special course of technological innovation here at Nanjing University."

"My side holds classes from time to time, and I will make an announcement in advance, and then interested students can come and listen. When the situation on my side is a little bit more stable, I will start a special class."

He originally taught a course in computational materials science, but when he was studying KL-66 materials, he accidentally discovered something in the strong correlation system.

Later, during the research process, it was found that it seemed to promote the miniaturization of controllable nuclear fusion devices, so the idea of ​​starting the class was cancelled.

After all, compared with the importance of miniaturized and controllable nuclear fusion reactors, offering computational materials courses is dispensable.

Hearing this, Tan Shaoyuan nodded with a smile, and said, "Yes, you can arrange this kind of Academician Xu. If you need to start a class, you can tell me at any time, and I will help arrange it."

Xu Chuan smiled and said, "No problem."

"Then don't disturb Academician Xu's work."

Tan Shaoyuan left the office with a smile, while Xu Chuan picked up the list materials in his hand and read them.

"Professor, are you recruiting new students?"

In the office, Cai Peng, who had been silent all this time, looked over curiously after Principal Tan left.

Xu Chuan nodded, and said, "Well, taking advantage of the relative leisure time in the last few months, I plan to take a few students with me."

Cai Peng asked excitedly: "Then I will be a big brother from now on?"

Xu Chuan glanced at him and said, "You should think about how to graduate."

Cai Peng: "\\φ(゜▽゜*)\\"