Scholar’s Starry Sea

After receiving the 3rd day of the Guo Award, Wu Bin ushered in his graduation defense.

In the defense room, Wu Bin is describing his essay.

"As mentioned above, the current maximum transition temperature of iron-based superconductors has reached 55K, breaking the McLean limit of 39K, and has entered the range of over-temperature conductors. Although there are still shortcomings, but... …"

Hearing this, Academician Chen Xianhui, who had been sitting quietly there, suddenly asked: "Then how much do you think the temperature will exceed when iron-based superconductivity can do a lot?"

Wu Bin, who was about to put the PPT down, listened for a moment and thought about replied: "At least the temperature of liquid nitrogen should exceed 77K."

After listening to nodded, Chen Xianhui moved a chair to it. Patted next to him said: "Come and sit down. I have read your paper. In fact, it is very good. I believe that your level does not require me to do any verification. I prefer to hear your opinion on superconductivity. "This..." Wu Bin scratched his hair. "On superconductivity, I just just entered it. Talking about understanding in front of Professor Chen, I really feel a little bit okay. Bottom line."

We must know that currently the leading position of iron-based superconductivity in China is Professor Chen Xianhui’s group, which is definitely in the Grandmaster category.

"haha." Chen Xianhui smiled twice, "Don't be nervous, just say what you think."

"Okay, since Professor Chen you have said so, I’ll try.” Wu Bin said and sat next to Chen Xianhui. “In fact, after reading a lot of papers on high-temperature superconductivity, what I am most puzzled about is the specific mechanism of high-temperature superconductivity. The existence of medium and long-range magnetic order phases is considered to be one of the reasons that may cause superconductivity, but this is only a possibility, or only one of them."

Chen Xianhui nodded, "Yes, because in high temperature superconductivity There are many complex phase diagrams such as charge density waves, spin density waves, long-range ferromagnetic antiferromagnetic superstructures, etc., so the mechanism research has been very difficult, so this is not just your doubts, but the whole academic community. Doubt."

Hearing this, Wu Bin suddenly stood up and walked to the blackboard and wrote [SmFeAsO1-xFx] and [Ba1-xKxFe2As2] with chalk.

"I saw I wrote a paper of yours, which describes the change of the superconducting critical temperature and the spin density wave transition temperature in these two systems through the conversion of oxygen and iron. I found that the oxygen isotope effect at the critical temperature is very small. But the iron isotope effect is very large."

"What’s even more amazing is that the isotope exchange of this system has the same effect on the critical temperature and the spin density wave transition temperature. Does this indicate that the electroacoustics in this system Does sub-interaction play a certain role in superconductivity?"

"hahaha." Chen Xianhui suddenly laughed loudly after listening to Wu Bin’s question, "No wonder Professor Liu took special care of me to make me not believe I only know a little bit about what you said, and I don’t know much about it."

"Ask this question shows that you are not at all what you said about superconductivity, just just entered Ah."

"Huh? Did Professor Liu say that to me?" Wu Bin's expression was a little embarrassed. These days, he is hacked when he speaks carefully.

Looking at Wu Bin’s embarrassed expression, Academician Chen Xianhui waved his hand and said, “It’s a good thing to be in awe in front of knowledge. Those who like to talk full of words really don’t understand. I appreciate your quality. ."

"Thank you Professor Chen for your compliment."

"As for the question you just asked, this is not just a simple mechanism of electrophonon interaction. There is a coupling between spin and phonons..."

Speaking of rise, Professor Chen Xianhui also went to the blackboard and picked up a chalk and began to draw a relationship diagram.

...

Outside the defense, Jin Yunxia was waiting anxiously, holding Wu Shiqiang beside her from time to time and whispering: "Why haven't this come out yet? My son just said Doesn’t it take much time? Is there something wrong?"

Because Director Jiang told Wu Bin that once his graduation defense is over, the school will help him hold a graduation ceremony for him alone. So Wu Bin simply let his parents live next to the school for two days, and then go back after attending the graduation ceremony.

And after Jin Yunxia heard the news that Wu Bin was going to graduate today, she said that she would also come together, so she waited at the door of the defense room.

Wu Shiqiang patted her on the back and said: "Aiya, don’t worry. If your son says there is no problem, it will be okay. Believe him."

"That’s what I said. ...But it's too long."

At this time, Li Yan, who was also waiting on the sidelines, smiled and said: "Don't worry, Aunt, replies to this kind of thing, it will only show them after a long time. There is a lot to talk about, and the respondent tutor doesn’t want to talk a lot with dissatisfied students."

Jin Yunxia patted her chest and said: "Then I can rest assured, thank you You, little classmate, I remember your name is...Li Yan, right?"

"Yes, it's me." Li Yan nodded.

"Thank you for taking care of my son at school, and waiting for him to reply."

"Where is Aunt, it is your son who takes care of me, he can help me It’s too much, I’m his follower."

"Oh, you can’t say that. It’s okay for students to help each other. What kind of follower should not follow the class." Jin Yunxia smiled and waved her hand, and then again looked towards Lin Ziqi, who was standing next to Li Yan and kept silent, said: "That...Aunt has a bad memory, have we met this classmate?"

Lin was asked Ziqi immediately stood up straight and nodded and said: "en! Last summer, Aunt, we met at the gate of the library when you visited Wu Bin."

"Oh~~Yes, I remember." Jin Yunxia patted her forehead: "Look at my memory, but you seem to be different from that time?"

Lin Ziqi lowered her head and said, "Probably because of me back then. Wear glasses."

"Yes, yes, yes." After that, Jin Yunxia approached Lin Ziqi and took a look: "It's better not to wear glasses, what a beautiful little girl."

"Thanks...Thank you Aunt." Lin Ziqi blushed and thanked.

"Thank you for coming to wait for Wu Bin. I am relieved to know that he has so many friends at school."

Lin Ziqi hurriedly waved his hand and said, "No thanks, No thanks."

Just when Jin Yunxia wanted to ask anything else, the door of the defense room suddenly opened, and Wu Bin and Professor Chen Xianhui walked out of it together.

Looking at the few people waiting outside the door, Wu Bin said with a smile: "Everyone, I graduated."

Now Jin Yunxia's hanging heart is completely let go , Excitedly went up and hugged Wu Bin, then bowed to Professor Chen Xianhui: "Thank you teacher, thank you teacher."

Chen Xianhui quickly held Jin Yunxia and said: "Don't thank me, your son Very good, it is his own ability to pass the defense, and it has nothing to do with me."

"Thank you, thank you." Jin Yunxia nodded and said happily.

PS: Found that it happened to be the third hundredth chapter~Sahua