The Science Fiction World of Xueba

For the next month, Pang Xuelin stayed at USTC.

Normal-temperature superconducting materials are the key to the electromagnetic orbital ejection system. Pang Xuelin is going to do his best to solve the problem of normal-temperature superconducting before the next time-traveling time arrives.

Of course, in addition to discussing the experimental plan with Cao Yuan and the others, Pang Xuelin was also invited to hold two lectures at USTC, each of which was full of seats and attracted many students from USTC to actively participate.

As for the experiment, Pang Xuelin could not provide much help, so he could only provide some suggestions. The specifics of how to do it could only be handed over to Cao Yuan and Dong Chenglin.

Fortunately, both Cao Yuan and Dong Chenglin are excellent experimental physicists, and basically perfectly presented the experimental effect that Pang Xuelin wanted.

A month passed by in a flash.

This afternoon, with Zhou Tong's cheers, everyone in the laboratory focused their attention on Zhou Tong.

Even Pang Xuelin is no exception.

Only then did Zhou Tong realize that he had lost his composure, stood up a little embarrassed, and said with a smile: "Professor Pang, Professor Cao, I have already processed all the data on the condensation energy of the superconducting state and the energy difference between the superconducting state and the normal state. .”

The crowd immediately swarmed over.

Pang Xuelin said: "How about the accuracy?"

Zhou Tong said: "Professor Pang, this is the result of my measurement and analysis of 200,000 sets of data, and the estimated error is no more than one ten thousandth."

Pang Xuelin nodded, with a satisfied smile on his face, and said: "Thanks for your hard work, you can print out the data and give me a copy later."

"good."

Zhou Tong nodded.

Cao Yuan and the others also heaved a sigh of relief.

For the past month, basically 24 hours a day, the lights in the lab have been on.

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

It is also because of such desperate efforts that they were able to complete the experimental work in just one month.

Of course, with everyone working so hard, material incentives are naturally indispensable.

Even Pang Xuelin, Wei Wenxuan and Tan Song, two doctoral students, gave treatment far beyond 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 of the work to me."

"good!"

Cao Yuan nodded.

Pang Xuelin didn't stay any longer. After getting the data, he went straight back to the expert building arranged for him by the University of Science and Technology of China.

Zuo Yiqiu was bored watching TV in the living room.

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

Zuo Yiqiu was free, except for occasionally helping Pang Xuelin with the administrative affairs of Jiang University and Qiantang Laboratory, the rest of the time was basically free for her.

Seeing Pang Xuelin enter the room, Zuo Yiqiu asked curiously, "Professor Pang, why did you come back so early today?"

In the past, Pang Xuelin would not stay in the laboratory until eleven or twelve o'clock in the evening, and would not come back, but now 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 I'm going to retreat for a while. You help me to block the visitors outside, and don't let people disturb me."

Zuo Yiqiu was slightly taken aback, and asked curiously, "Professor Pang, how long are you going to retreat this time?"

"It's as short as a week, and as long as a month. If there is really something very important, you can come to me again."

Pang Xuelin said with a smile.

"so long?"

"What's wrong?"

"No...nothing? By the way,

Professor Pang, you just retreated like this, what will Qi Xin and Yao Bingxia do when they come to you? "

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

"oh."

Zuo Yiqiu nodded and said no more.

Pang Xuelin ignored Zuo Yiqiu and went straight upstairs.

When he came to the study, Pang Xuelin called Qi Xin and Yao Bingxia respectively, and told them that he would be in retreat for a period of time, and he could not contact them every day.

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

Afterwards, Pang Xuelin took out the manuscript paper and began formal retreat research.

Time passed day by day.

one day, two days...

a week, two weeks...

Before I knew it, half a month had passed.

After another night, Pang Xuelin rubbed his eyes tiredly.

The high-intensity mental work day and night, even after a genetically modified body, is somewhat overwhelming.

Pang Xuelin stretched for a long time, looking at the data on the manuscript paper in front of him, his eyes became brighter than ever before.

Not surprisingly, a brand new physical theory system has taken shape before his eyes.

"It's finally done."

Pang Xuelin said to himself.

He came to the window and opened the curtain with a snap.

The morning light outside the window is faint, and the chirping of birds can be heard.

On the nearby road, there are already many teachers and students doing morning exercises.

The rays of the rising sun could already be seen in the distance, and Pang Xuelin narrowed his eyes slightly, as if seeing the light of the new world.

Afterwards, he picked up the mobile phone that he hadn't used for a long time and dialed Cao Yuan's number.

Cao Yuan was obviously still sleeping, and when the phone was connected, his voice was still muffled.

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

"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 said in disbelief, "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'll go find you!"

"Don't worry, you call everyone over, and we'll meet in the laboratory at 8:30."

"Oh, okay."

Cao Yuan hesitated for a moment, resisting the urge to immediately go to Pang Xuelin.

When Pang Xuelin came out of the house, he smelled the smell of breakfast coming from the kitchen.

Gululu...

Only then did Pang Xuelin feel the protest from his stomach.

For half a month, he studied day and night, and the average sleep time per day was less than two hours, and Zuo Yiqiu basically sent him to solve the problem of eating.

Perhaps because of the noise, Zuo Yiqiu came out of the kitchen, looked at Pang Xuelin in surprise, and said, "Professor Pang, have you left the customs?"

Pang Xuelin was a little surprised and said: "Are you making breakfast? Why don't you go to the cafeteria to buy it?"

Zuo Yiqiu glared at Pang Xuelin angrily, and said, "Professor Pang, I cooked all the meals you ate during this time."

"You made it?" Pang Xuelin was taken aback for a moment, then realized it immediately, and said with a smile, "I said how the food is so much more delicious recently."

Zuo Yiqiu rolled his eyes.

Why couldn't she see that Pang Xuelin was trying to make amends on purpose? With his level of devotion in research, it's no wonder that he could taste the food.

Thanks to myself, I was worried that the food in the cafeteria of the University of Science and Technology would not suit Pang Xuelin's appetite, so I worked so hard to cook for him for so many days.

But Zuo Yiqiu suppressed his anger and said, "Professor Pang, are you going out?"

Pang Xuelin nodded and said, "Go to the laboratory later."

Zuo Yiqiu said: "Then wait a moment, I cooked preserved egg and lean meat porridge, it will be ready soon."

After more than ten minutes, the steaming hot preserved egg porridge was brought 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 will we stay at HKUST?"

Pang Xuelin smiled and said, "If there are no accidents, you should be able to return to Jiangcheng today."

"today?"

Zuo Yiqiu's eyes widened, a little surprised.

"What's wrong?"

Pang Xuelin was puzzled.

"No... nothing."

Zuo Yiqiu quickly shook his head.

After breakfast, Pang Xuelin went straight to the laboratory.

Seeing Pang Xuelin's figure disappear at the door, Zuo Yiqiu quickly took out his mobile phone and made a call.

...

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

Pang Xuelin said: "Everyone is here, right? Let's go, let's go to the conference room to talk."

Everyone nodded and followed Pang Xuelin into the conference room.

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

Dong Chenglin spoke first.

Cao Yuan, Zhou Tong and the others all focused their attention on Pang Xuelin, with hopeful expressions on their faces.

If it were someone else, everyone would naturally have doubts.

But Pang Xuelin was different, not to mention the academic status of this boss, the super academic ability he showed before made everyone full of confidence in him.

Pang Xuelin smiled slightly, nodded and said: "I have indeed completed the construction of the theory of superconductivity."

"Professor Pang, tell us quickly."

Zhou Tong looked like a little girl, and couldn't wait to say it.

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

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

Pang Xuelin no longer entertained everyone's appetite, and said with a smile: "Okay, then I will talk about it first. During this period of time, I have proved that the one-dimensional and two-dimensional narrow-band (including next-nearest-neighbor hopping, etc.) The TJ model will not present the superconducting long-term program of S-wave nearest-neighbor pairing, generalized η pairing, generalized off-site Q-pairing, and dx2-y2 wave pairing. If in the charge excitation spectrum of the system If there is an excitation energy gap, these long pairing programs will also be ruled out at zero temperature, and our results are valid for any J value and any electron filling."

While talking, Pang Xuelin picked up the marker pen and started writing on the whiteboard behind him.

Including Cao Yuan, everyone focused on the formulas on the whiteboard 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-term programs are formed at low temperatures, such as mechanisms such as BCS and BEC. However, if we consider The interaction force, if the attraction is strong enough, then the transition temperature will be high enough."

"For example, strongly correlated systems, heavy fermion compounds, copper-based superconductors and iron-based superconductors, and even hydrogen sulfide and hydrogen lanthanide under high pressure are all strongly correlated materials. The high-temperature superconductors established by the strong correlated system The mechanism of conduction is the superconducting long program enhanced by quantum fluctuations. In the condensed matter system, all long programs are obtained by perturbation on the basis of the Fermi liquid ground state. For example, superconducting, charge density wave [CDW], Fermi sequence [Stoner FM], antiferromagnetic sequence [AFM] or spin density wave [SDW], etc. Therefore, our understanding of these long programs is consistent, and the Fermi surface is destabilized by some mechanism. gap, thereby establishing a long program and keeping it stable at low temperatures, as long as the thermal fluctuation energy scale kT is close to the energy gap, the long program will be destroyed."

"Similarly, this also understands why various long programs always compete or suppress each other. In fact, it is to compare which of these long programs can open a larger energy gap at the Fermi surface. The system establishes a long-term program, so as not to build another at the same time."

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

...

Time passed by every minute and every second.

Before I knew it, an hour passed.

The whiteboard was also filled with writing by Pang Xuelin.

Finally, Pang Xuelin put down the marker pen, pointed to the last formula on the whiteboard and said: "Through this formula, we can substitute the parameters of certain materials into it, and predict at what temperature and pressure they will become superconductors. "

Pang Xuelin turned around and looked at the crowd who were still in daze and shock.

Wei Wenxuan and Tan Song, the two doctoral students, looked blank, as if they were listening to a scripture.

Dong Chenglin and Zhou Tong were lost in thought.

Only Cao Yuan, who reacted immediately, clapped his hands gently.

clap clap...

Applause soon resounded throughout the meeting room.

Cao Yuan said: "Professor Pang, congratulations, this is completely a Nobel Prize-level achievement!"

Seeing that some people in the team still didn't seem to understand, Cao Yuan said: "In general, Professor Pang's work explains why most superconductors can only exhibit superconductors below the temperature of liquid nitrogen and liquid helium. conduction state, or under the condition of millions of atmospheric pressures, high-temperature superconducting properties can be exhibited. An accurate calculation formula is even given, through which we can deduce the superconducting transition of some superconducting materials Temperature and external conditions can even deduce the state of some materials when they are in the superconducting state."

At this time, Dong Chenglin also nodded and said: "It's really amazing, Professor Pang. If there is no accident, with this theory, the Nobel Prize in Physics should be in your pocket. But I want to fully understand what you are doing. A set of theory, I am afraid that requires a very good mathematical foundation."