MTL - The Science Fiction World of Xueba-Chapter 411 Superconducting theory

For the next month, Pang Xuelin stayed at the Chinese University of Science and Technology without leaving.

Room temperature superconducting materials are the key to the electromagnetic orbit ejection system. Pang Xuelin is ready to do his best to fight for the room temperature superconductor before the next crossing time comes.

Of course, in addition to discussing experimental schemes with Cao Yuan and Pang Xuelin, he was also invited to hold two lectures at the Chinese University of Science and Technology. Each lecture was full, attracting the active participation of many Chinese university students.

As for the experiment, Pang Xuelin can provide little help, so he can only provide some suggestions. What to do specifically can only be given to Cao Yuan and Dong Chenglin.

Fortunately, Cao Yuan and Dong Chenglin are both excellent experimental physicists, and they basically perfectly show the experimental results that Pang Xuelin wants.

A month passed by.

This afternoon, accompanied by a cheer from Zhou Tong, everyone in the laboratory focused on Zhou Tong.

Even Pang Xuelin is no exception.

Zhou Tong then realized that he was dysfunctional, and stood up a bit embarrassed, and laughed: "Professor Pang, Professor Cao, superconducting state condensation energy data and superconducting state and normal energy difference data, I have all processed . "

The crowd suddenly swarmed over.

Pang Xuelin said: "How about accuracy?"

Zhou Tong said: "Professor Pang, this is the result of my measurement and analysis of 200,000 sets of data, and the expected error is not more than one ten thousandth."

Pang Xuelin nodded, a satisfied smile on his face, and said, "It's hard. You can print the data to me later."

"it is good."

Zhou Tong nodded.

Cao Yuan and they were relieved.

In the past month, basically the laboratory lights were on 24 hours a day.

Including Cao Yuan and Pang Xuelin, each person works at least 14 hours a day.

Because of this desperation, they were able to complete the experimental work in just one month.

Of course, everyone is working so hard, and material conditions are naturally indispensable.

Even two doctoral students, Wei Wenxuan and Tan Song, Pang Xuelin gave far more treatment than ordinary doctoral students.

At this time, Pang Xuelin said with a smile: "Everyone has worked hard this month, Professor Cao, and then I will give you a good vacation and rest for a while, and leave the rest to me."

"it is good!"

Cao Yuan nodded.

Pang Xuelin was not staying too much. After getting the data, he went straight back to the expert building arranged by the University of Science and Technology for himself.

Zuo Yiqiu is watching TV in the living room with some boredom.

This month, Pang Xuelin spent most of his time in the laboratory.

Zuo Yiqiu took a rest, except for occasionally helping Pang Xuelin handle the administrative affairs of Jiangda and Qiantang Labs. For the rest of the time, she was basically at her disposal.

Seeing Pang Xuelin entering the house, Zuo Yiqiu was curious: "Professor Pang, why are you back so early today?"

In the past, Pang Xuelin didn't stay in the laboratory until eleven or twelve in the evening and would not return. It is only after two o'clock in the afternoon.

Pang Xuelin said with a smile: "The data from the laboratory has come out, and then I will retreat for a while. You help me stop visitors outside, don't let people disturb me."

Zuo Yiqiu hesitated for a moment, wondering, "Professor Pang, how long are you going to retreat this time?"

"A week is short and a month is long. If there is something very important, come to me again."

Pang Xuelin said with a smile.

"so long?"

"what happened?"

"No ... nothing? By the way, Professor Pang, you are so closed. What will Qi Xin and Yao Bingxia look for you?"

Pang Xuelin said: "I'll talk to them later and they will understand."

"Oh."

Zuo Yiqiu nodded, no more words.

Pang Xuelin ignored Zuo Yiqiu and went straight upstairs.

In the study, Pang Xuelin called Qi Xin and Yao Bingxia respectively, telling them that they would be in retreat for a period of time, and could not contact them every day.

After finally soothing the two daughters, Pang Xuelin called his parents and Liu Tingbo, Xu Xingguo, Li Changqing, Shi Yi and others to notify them one by one.

Subsequently, Pang Xuelin took out the manuscript paper and started the formal retreat study.

Time passes day by day.

One day, two days ...

One week, two weeks ...

Unconsciously, half a month has passed.

After another night, Pang Xuelin rubbed his eyes a little tired.

High-intensity mental work is carried out day and night, even if the body is genetically modified, it is still a bit too much.

Pang Xuelin stretched his waist long, looking at the data on the manuscript paper, his eyes became brighter than ever.

Not surprisingly, a whole new system of physics theory has taken shape in his eyes.

"It's finally done."

Pang Xuelin said to himself.

He came to the window and slammed the curtain open.

The morning light outside the window was faint, and you could hear the birds chirping.

There are already many teachers and students doing morning exercises on the nearby roads.

You can already see the sunrays in the distance, Pang Xuelin's eyes narrowed slightly, as if seeing the light of the new world.

Later, he picked up the unused cell phone and dialed Cao Yuan's phone.

Cao Yuan was apparently still asleep. When the call was connected, his voice was still confused.

But Pang Xuelin's words made Cao Yuan aroused and completely sobered.

"Professor Cao, I think I have found a unified theory of superconductivity."

"What?" Cao Yuan got up from the bed all of a sudden, and wondered, "Professor Pang, say it again."

Pang Xuelin said with a smile: "Professor Cao, I have found the theoretical mechanism of superconductivity."

"Professor Pang, are you in the expert building now? I used to look for you!"

"Don't worry, you call everyone over, we'll see you in the lab at half past eight."

"Oh, okay."

Cao Yuan hesitated a moment, and pressed his urge to go to Pang Xuelin immediately.

Pang Xuelin came out of the room and smelled the smell of breakfast from the kitchen.

Grunt ...

Pang Xuelin felt the protest from his stomach.

During this half-month period, he researched day and night, and the average daily sleep time was less than two hours. The problem of eating was basically solved by Zuo Yiqiu.

Perhaps he heard the movement, Zuo Yiqiu came out of the kitchen, and looked at Pang Xuelin with surprise: "Professor Pang, are you out of customs?"

Pang Xuelin said, "You are making breakfast? Why don't you buy it in the cafeteria?"

Zuo Yiqiu gave a puffy glance at Pang Xuelin and said, "Professor Pang, I made all the food you eat during this time."

"You made it?" Pang Xuelin took a moment's notice, reacted immediately, and quickly laughed, "I said how delicious the food has been a lot lately."

Zuo Yiqiu rolled his eyes.

How could she not see that Pang Xuelin was deliberately remedying it, and with the degree of investment in his research, it was strange that he could taste the food.

I was also worried that the food in HKUST's cafeteria would not fit Pang Xuelin's appetite, and worked so hard for him for so many days.

However, Zuo Yiqiu still kept his mind down and said, "Professor Pang, are you going out?"

Pang Xuelin nodded and said, "Wait for the lab."

Zuo Yiqiu said: "Then wait a minute, I cooked the lean porridge with preserved eggs, and it will be all right."

After more than ten minutes, the steamed preserved eggs and lean meat porridge were moved to the dining table.

The two were drinking porridge at the dining table. Zuo Yiqiu sat opposite Pang Xuelin and said, "Professor Pang, how long are we going to stay at the University of Science and Technology?"

Pang Xuelin laughed: "If nothing unexpected, we should be able to return to Jiangcheng today."

"Nowadays?"

Zuo Yiqiu's eyes widened and he was a bit surprised.

"what happened?"

Pang Xuelin wondered.

"No ... nothing."

Zuo Yiqiu quickly shook his head.

After breakfast, Pang Xuelin went straight to the laboratory.

Watching Pang Xuelin's figure disappear at the door, Zuo Yiqiu quickly pulled out his cell phone and dialed a phone number.

...

By the time Pang Xuelin arrived at the laboratory, Cao Yuan, Zhou Tong, and Dong Chenglin had all arrived at the laboratory.

Pang Xuelin said, "Is everyone here? Let's go and talk in the conference room."

The crowd nodded and followed Pang Xuelin into the conference room.

"Professor Pang, I heard Lao Cao said that you have completed the theoretical construction of superconducting theory?"

Dong Chenglin took the lead.

Cao Yuan and Zhou Tong both focused their eyes on Pang Xuelin, with hopeful expressions on their faces.

If you change to others, everyone will naturally have doubts.

But Pang Xuelin is not the same, and not to mention the academic status of this big man, the super academic ability he showed before alone made everyone full of confidence in him.

Pang Xuelin smiled and nodded: "I did complete the construction of the superconducting theory."

"Professor Pang, tell us soon."

Zhou Tong can't wait to say what she looks like.

In fact, not only Zhou Tong, almost everyone has similar eyes.

Everyone knows what it means to complete the theoretical construction of the superconducting mechanism.

Pang Xuelin no longer applauds everyone, and said with a smile: "Okay, let me talk about it first. During this time, I proved that the multi-dimensional body function solves the one-dimensional and two-dimensional narrow bands at any non-zero temperature. (Including next-nearest neighbor jumps, etc.) The TJ model will not show superconducting length procedures for S-wave nearest-neighbor pairing, generalized η pairing, generalized out-of-place Q pairing, and dx2-y2 wave pairing. If in the system's charge excitation spectrum There is an excitation energy gap, so these paired long programs are also excluded at zero temperature, and our results are true for any J value and any electron filling. "

As he spoke, Pang Xuelin picked up the marker and wrote on the whiteboard behind him.

Everyone, including Cao Yuan, looked at the formula on the whiteboard intently, while trying to listen to Pang Xuelin's explanation.

Pang Xuelin continued: "The simple understanding is that in superconductors, thermal fluctuations will destroy superconductivity, and various long programs are formed at low temperatures, such as BCS and BEC mechanisms. However, if we consider Interaction force, if the attraction is large enough, the transition temperature will be high enough. "

"For example, strong correlation systems, the currently experimental heavy fermion compounds, copper-based superconductors and iron-based superconductors, and even hydrogen sulfide and lanthanide under high pressure are all strongly correlated materials. The mechanism of the conductance is the superconducting long program enhanced by quantum fluctuations. In the condensed state system, all long programs are obtained by applying perturbations based on the ground state of the Fermi liquid. Ferromagnetic sequence [StonerFM], antiferromagnetic sequence [AFM] or spin density wave [SDW], etc. Therefore, our understanding of these long programs is consistent, and the Fermi surface instability opens the energy gap through some mechanisms , And then establish a long program and keep it stable at low temperatures, as long as the thermal fluctuation energy standard kT is close to the energy gap, the long program will be destroyed. "

"Similarly, this also understands why the various long programs always compete or suppress each other. In fact, it compares which of the long programs which can open the energy gap at the Fermi surface, and the system establishes a long Program, you won't create another at the same time. "

"The difference between a strong correlation system and a traditional condensed matter system is that the spin correlation between electrons must be considered. This correlation causes quantum fluctuations, and its ground state changes from a Fermi liquid state to a spin liquid state or other state. This leads to strong quantum fluctuations in the magnetic sequence, the magnetic sequence is suppressed, and the superconducting sequence is established. What is more interesting is that the quantum fluctuations in the magnetic sequence will also strengthen the supersequence. Leading order. Because the spins of the electrons are close to the Mote state, the superconducting pairing interaction is strengthened and the transition temperature is increased. In ferromagnetic superconductors, etc., near the quantum phase transition point of the anisotropic ferromagnetic state, it is Quantum fluctuations strengthen superconducting states. "

...

Time passes by every minute. UU Kanshu www.uukanshu.com

Unconsciously, an hour passed.

The whiteboard was also written by Pang Xuelin.

In the end, Pang Xuelin put down the marker and pointed to the last formula on the whiteboard: "Through this formula. We can substitute some material parameters into it, and predict what kind of temperature and pressure they can become superconductors. "

Pang Xuelin turned to look at the crowd still in agitation and shock.

The two doctoral students, Wei Wenxuan and Tan Song, looked blank, as if listening to heavenly books.

Dong Chenglin and Zhou Tong were lost in thought.

Only Cao Yuan reacted for the first time and gently clapped his hands.

Poppy ...

Applause soon rang throughout the conference room.

Cao Yuan said, "Professor Pang, congratulations, this is the achievement of Nobel Prize level!"

Seeing that some people in the team still don't seem to understand well, Cao Yuan said: "In general, Professor Pang's work explains why most superconductors and why they need to be below the temperature of liquid nitrogen and helium. Conducted state, or only under the conditions of millions of atmospheric pressure, can show high-temperature superconducting properties. Even accurate calculation formulas are given. Through this formula, we can infer the superconducting transition of some superconducting materials. Temperature and external conditions can even deduce the state of some materials when they are in a superconducting state. "

At this time, Dong Chenglin also nodded and said, "It is really great, Professor Pang. It is not surprising that with this theory, the Nobel Prize in Physics should be in your pocket. But I want to fully understand your I am afraid that it requires a very good mathematical foundation. "