Chapter 161 Can the update speed be faster?

The problem was found though.

But I still don’t have any clue about the solution to the problem.

It is based on the original method to further seek optimization solutions.

Or should we use a better method to further reduce the error and obtain ideal numerical results?

Xu You doesn't have any good methods for this at the moment.

"Teacher, I will think about it when I get back and see if there is any better approximation method. Can you give me a copy of this paper? I promise not to spread it outside."

Wang Xiangwu and Zhao Weijia both trusted Xu You very much and readily agreed to Xu You's request.

"Of course, you can just copy it. If you have any other questions, you can contact me at any time."

Since Wang Xiangwu has taken the initiative to ask Xu You for help, he will naturally not trust Xu You.

After returning from Wang Xiangwu's laboratory, Xu Youxian returned to his dormitory.

Of course I went to pick up my suitcase.

Although we are looking for ways to solve problems, when the amount of knowledge is not enough, just thinking is definitely not enough.

Xu You still needs to further supplement relevant knowledge.

When they saw Xu You coming to the library, the library staff unanimously paid Xu You a attention salute.

Three full days have passed since Xu You last came to the library.

Originally, Xu You would come to the library once every two days.

Xu You also nodded to these staff members.

There was no way, Xu You came so often that he was already familiar with them.

Because Xu You seldom attends classes and rarely participates in various activities of the college.

Xu You is even more familiar with these library staff than he is with many of his college classmates.

With his precious suitcase in hand, Xu You searched the library again.

When Xu You reads a certain number of books.

A new problem also emerged.

That is, Xu You has read many books.

The update speed of library books is really not as fast as Xu You's reading speed.

Xu You wants to find a good book, and it is a book that he has never read, and it is becoming more and more difficult.

After coming out of the library, Xu You once again felt the gazes of the library staff.

Xu You looked at the librarian and hesitated to speak.

"What's wrong, classmate Xu You, is there any problem?"

Librarians also pay special attention to the library's largest customer.

"Teacher, I have something to say, I don't know whether I should say it or not."

"Classmate Xu You, please tell me quickly."

"Can the update speed of our library's books be a little faster? I'm already starting to have a book shortage."

The librarian said to himself, no matter how fast the update is, it is not enough for you to see it this way.

Sometimes, it's not a matter of money, but that there really aren't that many new books.

"Okay, classmate Xu You, I will help you report this matter."

"Okay, please excuse me, teacher."

After returning to the dormitory, Xu You sorted out the books and started a pleasant reading session.

Xu You has two ways of choosing books.

One is to look at some knowledge that may not be used temporarily, but may be used in the future as a reserve of knowledge.

The other way is to look at some of the knowledge that will be involved as it is now.

On this issue, Xu You also believes that approximate methods must be applied.

How to reduce the error caused by approximation to the greatest extent is the most critical issue.

"Huh? Mean field approximation method?"

At this time, Xu You suddenly discovered such a method.

In fact, Xu You had heard of this method before, but he hadn't really studied it carefully.

But this time, Xu You felt that this method was likely to be applied to this problem.

The mean field approximation is often used to study complex multi-body problems.

A huge number of interacting multi-body problems can be transformed into a single-body problem in which each particle is in a weak periodic field.

Although there have been no application examples of this method on similar problems.

But Xu You feels that you can still give it a try.

"It's not possible to apply it directly. It still needs to be optimized first."

Xu You opened the paper and optimized this method based on the characteristics of the problem being studied.

There are many formulas involved in this problem, so it is still very complicated to deal with.

"Starting from the basic interaction between the two-level system and the light field. The anti-spin wave term will quickly decay to zero as time evolves. This can definitely be ignored..."

Xu You deduced the formula step by step, taking every step with extreme caution.

"Huh~ I finally got the Hamiltonian out."

In this way, we can finally start to apply the mean field approximation.

"First, introduce a superfluid order parameter..."

Because the Hamiltonian calculated previously is very difficult to calculate specifically.

Xu You must calculate it through approximate methods, while maintaining extremely high accuracy and reducing errors as much as possible.

After another series of calculations, Xu You finally completed further derivation.

"The high-order fluctuation terms here can be ignored under the mean field approximation. In this way, the effective Hamiltonian can be calculated."

After writing the last formula, Xu You could finally breathe a sigh of relief.

Xu You didn't know if anyone had applied this method on similar problems before him.

But relying on Xu You's feeling, this new method will greatly reduce the error.

"Put in the data and verify it."

Although Xu You's feelings are usually very accurate.

However, further verification is still needed to finally prove whether the method is suitable.

Xu You input the effective Hamiltonian expression he had just derived into the software and started the fitting work again.

When Xu You saw that the newly emerged curve was closer to the theoretical curve, Xu You knew that his method should be correct.

"Sure enough, such an error is more ideal data!"

In order to ensure the applicability of this method, Xu You tested several other sets of data and further confirmed his ideas.

"In this way, this problem should be solved."

This time, Xu You spent less than half a day.

I haven't even read half of the books I just borrowed.

Xu You couldn't care less and quickly returned to Wang Xiangwu's laboratory with his computer and scratch paper.

Seeing Xu You coming back, Zhao Weijia asked:

"What's wrong, Xu You, do you need more data?"

Zhao Weijia subconsciously thought that Xu You came back to look for what he wanted because of insufficient information or data.

"No need. Senior brother, please ask Teacher Wang to come over. I have found a better approximation method."
Chapter completed!