In the living room, Xu Chuan and Mr. Yang exchanged some research directions of strongly correlated electronic systems.

I have to say that although this old gentleman is nearly 100 years old, his thinking is still quite clear, and he can rely on the knowledge in his mind to screen and eliminate a lot of directions.

This is extremely rare for a hundred-year-old man.

For Xu Chuan, although these exchanges are only some research directions and theories, they can still save him a lot of time and point out some directions, which is a great gain.

On the side, Qiu Chengtong, who was listening to his exchange with Mr. Yang, suddenly interjected: "Although condensed matter physics is not within the scope of my research, why don't you regard the electronic behavior in strongly correlated electronic systems as electronic liquids or electronic solids?" ”

"Such as Rattinger liquids, liquid crystal states, charge density waves, Wigner crystals, etc., perhaps explained from this aspect, can achieve your purpose?"

"E-liquid?"

Mr. Qiu abruptly interjected a sentence, which made Xu Chuan look at him suspiciously.

The old gentleman, who is famous for his mathematics, continued to explain: "Although my main research direction is not physics, I know that based on the idea of topological core rotation, a unified mathematical theory of quantum liquids has been developed. Including topological order, SPT/SET order, symmetric breaking order, and CFT-like gapless phase, etc. ”

"If you can explain the topological skeleton and local quantum symmetry of quantum liquids, and show that all n quantum liquids form a -condensed complete higher category, the equivalent type of which can be explicitly computed from a simple residual 1-category, maybe you can do what you need?"

"Starting from the realm of quantum liquids?"

These words made Xu Chuan stunned for a moment and fell into thought.

The strongly correlated electronic system comes from the interaction of electrons, without which there is no correlation between the movements of electrons.

To put it simply, if the interaction is strong, the correlation is strong, and if the interaction is weak, the correlation is weak, and the "strong" and "weak" here refer to the relative size, not the absolute size, depending on the competition between different energies within the system.

The same interaction is not the same for half-filled and full-band, or for massive electrons (flat-band electrons) and massless electrons (Dirac fermions).

In condensed matter physics, however, the behavior of an electronic system is often thought of as a gas (free electron gas).

The "electron" here can be a quasiparticle, such as a conduction band electron in a crystal, or a single particle excitation of other interaction systems – that is, a liquid that can still be seen as a gas by a simple approximation.

After all, when the interaction is small, it can be approximated with free electrons; The interaction will most often form a Mott insulator, and the degrees of freedom of the electron motion are frozen, and only the degrees of freedom of the spin are frozen.

In this case, an effective spin model can be obtained by expanding with large degrees of freedom.

From this point of view, it is indeed feasible to think of the movement of locked electrons in a strongly correlated electronic system as liquid or solid.

It's just that he can't figure out how to go on this road for a while.

After all, it often takes a long time to go from idea to research.

On the other side, in the living room, Mr. Yang and Mr. Qiu did not disturb Xu Chuan, who was in deep thought, and each thought about other directions and ideas.

Today's exchange of strongly correlated electronic systems is aimed at providing some ideas and directions for the young scholar in front of him, which they can still do.

As for the more specific calculations, I'm afraid it's up to him.

Whether it is Mr. Yang or Mr. Qiu, with their current age, it can almost be said that they no longer have the energy to complete the calculation of such a top-notch frontier problem.

Even in the first two years, Mr. Qiu still had the energy to study and advance the KZB equation problem.

But as year after year passes, the rate of aging will get faster and faster.

Science is always young, and they, the old people who have sunset, are no longer able to push forward new knowledge.

In the living room, Xu Chuan pondered for a long time before coming back to his senses.

Seeing that he was moving, Qiu Lao first looked over and asked curiously, "How is it?" ”

Xu Chuan thought for a moment and said, "There is a little bit of thinking, as for whether it can be done, we will study it again in the future." I have a lot of thanks for your ideas and theories today, but I'm really sorry for your trouble. ”

Old Mr. Qiu smiled and said, "What kind of trouble is this, as long as it helps you." ”

After a slight pause, he continued: "Of course, I am not very familiar with the direction of physics, and you don't need to stumble on the theory I proposed, maybe it is wrong. ”

This can be regarded as a preventive vaccination in advance to prevent Xu Chuan from stumbling in the direction he proposed. After all, he was not a pure physicist, and condensed matter physics was not in his field of study.

Xu Chuan nodded with a smile and said, "Don't worry, I've never been a person who stumbles on a road, when I feel that this road doesn't work, there is a high probability that I will give up on it." ”

"But now, I think I can still give it a try, at least I think it should work, and I feel like I can see the end."

On the other side, Mr. Yang seemed to remember something, and suddenly said: "Is this the scientific research intuition of a genius when he was young?" ”

After a slight pause, he continued: "When I used to study the Yang-Mills equation, I tried many ways to generalize the norm invariance to noncommutative groups, but I failed many times. ”

"Because U1 symmetry is easy symmetry and SU2 symmetry is non-symmetry, I have been stuck for a long time. It wasn't until one time when I decided to add a quadratic term that I only had this idea at the time, and I couldn't help but have the idea of the right path in my head. ”

"It was quickly confirmed that this idea was correct, and the new field theory was successfully introduced."

After a pause, he then sighed: "It's just a pity that in the later research, I almost never had this feeling of unusually clear, as if I could see the correct answer as long as the idea came out." ”

As he spoke, he looked at Xu Chuan and said as if asking: "I used to wonder why you could make such brilliant results at this age, but now it seems that you can often have this intuition when researching problems?" ”

Hearing Mr. Yang's emotion, Xu Chuan was stunned for a moment.

He seems to have this kind of intuition?

And it's not once or twice, when he studied mathematics before, whether it was when he was studying the Hodge conjecture or the NS equation, he could always rely on this feeling at key points to judge whether the path behind was appropriate.

Of course, it would be unrealistic to say that you can see the right answer at a glance.

But it's true that this feeling has helped him save a lot of time.

In the past, he always felt that this was a judgment brought about by the knowledge in his mind, but now listening to this old Mr. Yang, it seems to be a little different?

On the side, Mr. Qiu said with a smile: "Don't listen to his nonsense, what kind of scientific intuition, what he says is so metaphysical, what the gods are chattering, it is just an empirical feeling brought by knowledge." ”

"They are engaged in physics, and in the end they all develop towards theology, this old guy has this trend a few years ago, you kid don't listen to him, just seriously engage in your own research, this kind of thinking must be relied on, sows will go up the tree."

Hearing this, Xu Chuan coughed a little embarrassed.

He seems to be a physics guy.

PS: The second is to ask for a monthly pass.

Ahem, it was supposed to be today's three watches, but I found that I overestimated my strength, and it took a lot of time to check the information and understand the information paper today, and I will make it up laterˋ(°▽、°)