The end of the report does not mean that the report meeting is over.

For the results of the natural sciences such as mathematics and physics, the question session is the real challenge.

For many researchers, submitting a conference paper is nerve-wracking, and answering questions is even more difficult.

Because not only do the presenters have to answer the questions of everyone present, but sometimes those questions are often pretended to be humble, long speeches, loose self-presentations, and undisguised intellectual flaunting.

To put it simply, you may encounter some pretending β during the questioning session.

Of course, at Xu Chuan's briefing, this situation is not possible.

After all, it's about pretending. Ahem, when it comes to advanced operations, who can compare to him in his report meeting?

When the applause in the auditorium was a little weaker, Xu Chuan stood back on the lecture platform, picked up the microphone and said again:

"This concludes the report on the Harmonized Framework for Strongly Connected Electronic Systems, and if you have any questions, please feel free to ask them and I will do my best to answer them."

For strongly correlated electronic systems, the most important thing for the physics community is the introduction of dimension-space concepts and corresponding mathematical methods in the whole paper.

If you can master these things, then it will not be difficult to understand the paper.

As Xu Chuan's words fell, in the auditorium, arms were raised.

Starting from the front row, Xu Chuan began to answer questions.

In this kind of report meeting, the selection of people naturally follows the reporter's own arrangement.

The first to ask questions was Frank Verchek, Nobel Laureate in Physics '04 who specializes in condensed matter physics, astrophysics and particle physics.

The big guy asked two questions related to the calculation methods of low-dimensional mathematical theory, and sat down after getting the perfect answer from Xu Chuan.

He was followed by Michael Kosterlitz.

The 16-year Nobel Laureate in Physics focuses on condensed matter theory and one-dimensional/two-dimensional physics.

When Xu Chuan motioned for him to ask a question, Kosterlitz quickly stood up and took the microphone from the staff with some excitement and anticipation.

"When electron-electron correlation is introduced into topological quantum materials, complex and novel ordered phases will be generated in the system, but how to explain this mathematically remains a mystery."

"How does Professor Xu see this problem, and does it have a rigorous model and analytical solution?"

As a scholar of topological phase transitions and topological phases of matter, he has been looking for a way to unify topological phase transitions and strongly correlated electronic systems.

But unfortunately, even if he was able to use topology to study the topological phase transitions and topological phase matter of physical materials from a mathematical point of view, he still could not find a suitable way.

And now, in the young scholar on the stage, he sees hope for a breakthrough.

Of course, what he didn't know was that the path he longed for and hoped for had already been opened up.

On the report platform, hearing this question, Xu Chuan immediately knew the other party's thoughts.

To establish a unified theory for topological phase transitions and strong correlation systems, and then to study topological quantum materials in depth.

This is his work that he was still busy with a few days ago, but he didn't expect someone to go with him today.

After a deep sigh, Xu Chuan spoke: "This is one of the unsolved problems in the strong correlation system. Unify the strong correlation system and topological state of matter. ”

"Theoretically, it is possible to unify the topological states of matter into the framework of strongly correlated electronic systems, but I have not studied this aspect in depth, and perhaps you can consider a non-trivial multiband quantum geometry approach for hybrid hybrid orbital features."

"This route is now manifesting a multitude of physical phenomena that can also be explained mathematically, perhaps by extension."

Although he had completed the theory, he was unable to explain it explicitly or explain his thesis.

After all, topological quantum materials involve the study of quantum computers, and the importance is quite high.

But at the report meeting, the fellow scholars in the audience had already made questions, and it was impossible for him not to say anything about it.

Listening to Xu Chuan's answer, Professor Kosterlitz fell into thought, and unconsciously sat down on his own.

Seeing this, Xu Chuan skipped him and continued to ask questions.

He was followed by Professor David Gross, the head of CERN.

Like Frank Verchek, he is also the Nobel Prize in Physics '04.

And nominally, this big bull is still Xu Chuan's grandfather.

Because he was Witten's mentor, theoretically on the same level as Alexander Grothendieck.

Of course, in terms of influence in their respective fields, Gross is certainly not as good as Grothendieck. After all, the latter is known as the founder of modern algebraic geometry and the greatest mathematician of the 20th century.

But Professor Gross's achievements are not low, and they can even be said to be very high.

He is the founder of the 'hybrid string theory', the founder of asymptotic freedom in the theory of strong interactions, one of the main founders of quantum chromodynamics, and is recognized as a leader in modern physics.

In today's physics world, his status does not mean that he can compete for the top three, but there should be no problem in fighting for the top five.

On the one hand, the unified framework theory of strongly correlated electronic systems is indeed in his research scope.

On the other hand, it is preparing to dock with Xu Chuan to exchange and communicate cooperation on the construction of CERN and Huaguo's large strong particle collider.

Although CERN is still debating whether to continue building the high-brightness LC-LHC Hadron Collider, I am afraid that there is little hope.

With the rise of China, the decline of the United States and the European Union is inevitable.

In the economic downturn, the importance of the large strong particle collider, which is a costly, extremely cumbersome to maintain, and requires a lot of money, is not so important.

Of course, at the briefing today, the question he asked had nothing to do with the collider, but only from a strongly correlated electronic system.

After all, this is the unspoken rule of the conference, and it is also the necessary respect and etiquette for the academic speaker.

Standing up, Professor Gross thought about the language for a moment, and then spoke: "On page 31 of the paper, I noticed the topological insulator effect of the strongly correlated electron effect in the two-dimensional state that you proposed. ”

"In this study, we first propose a minimum continuous model of the P+IP exciton phase, and propose a new topological invariant, the chiral Chen number, to describe the topological properties of the system."

"But in the two-dimensional minimum two-component model, although the traditional Chernition number of the topological exciton insulating phase is zero, it has one-half of the chiral Cherch, can you explain this?"

Hearing this, Xu Chuan lowered his head and flipped through the paper: "Thirty-one pages?" ”

"In simple terms, this new topological insulator is formed by exciton condensation of the P+IP wave function, and its mechanism is similar to that of the P+IP wave Cooper pair condensation, which leads to the famous topological superconductor."

"In the vortex of topological superconductivity, there will be Majorana fermions, and in the vortex of topological exciton insulators, there will be quasiparticles of 1/2 charge. However, unlike P+IP topological superconductors and Chern insulators, the traditional Chern number of this new topological exciton insulator is zero, so its topological properties are described by the newly proposed "Hand Manifest Number" of the research group. ”

"In addition, the condensation of the P+IP exciton can also lead to the breaking of the symmetry of in-plane spontaneous magnetization and time inversion"

Before Xu Chuan could finish his sentence, Professor David Gross interrupted him.

"What I know, and what I want to know, is how do you define that a strong electron-electron interaction produces a scattering channel with p-wave symmetry."

"If I'm not mistaken, this part of the theory involves small polarons in a strong electro-phonon interaction system, but this is still an unsolved puzzle."

Standing in the audience, David Gross looked at the young man on the podium and slowly voiced his questions.

His voice was not loud, but it exploded throughout the auditorium like a thunderbolt, attracting the attention of everyone present.

Listening to his mentor's question, Edward Witten's dark green pupils instantly condensed, and his breathing became short.

This is a flaw that he has not discovered, and even the entire physics community is afraid that few people have noticed this extremely subtle key point.

Professor Michael Kosterlitz, who had just finished asking the question, was stunned for a moment, then quickly bent down and flipped out the paper from the backpack on the corner of the chair, and found page 31 of the paper.

Looking at the theories and mathematical formulas on the paper, he quickly calculated in his head.

The small polaron problem of strong electro-phonon interaction systems is a problem in strong electron-phonon interaction systems. It has been extensively and deeply studied in the 60~80s of the 20th century.

However, with the discovery of strong electron-electron coupling systems represented by high-temperature superconductors, this research is no longer the mainstream. There is no complete set of theoretical images to solve this problem in a unified way.

He didn't expect to find this deeply hidden point in this paper.

Now, for Professor Xu, this may be a 'fatal' flaw in the unified framework of strongly correlated electronic systems.

PS: There is one more chapter in the evening