Xueba's Sea of ​​Stars

Chapter 296 Graduation
On the third day after receiving the Guo Award, Wu Bin ushered in his graduation defense.

In the defense room, Wu Bin was describing his thesis.

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

Hearing this, Academician Chen Xianhui, who had been sitting there quietly, suddenly asked: "Then how high do you think the temperature will be for iron-based superconductivity to be promising?"

Wu Bin, who was about to release the PPT, was taken aback after listening, thought for a while and replied: "At least the temperature of liquid nitrogen must exceed 77K."

After listening, Chen Xianhui nodded, moved a chair to his side, patted it and said, "Come and sit, I have already read your thesis, it is very well written, and I believe that your level does not require me to do it again." What verification, I would like to hear your understanding and understanding of superconductivity now."

"This..." Wu Bin scratched his hair, "I'm just getting started in superconductivity, and I really don't know how to understand it in front of Professor Chen."

You must know that Professor Chen Xianhui's group is currently at the forefront of iron-based superconductivity in the country, and it can definitely be said to be in the master category.

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

"Okay, since you have said so, Professor Chen, I will give it a try." After Wu Bin finished speaking, he sat next to Chen Xianhui, "Actually, after consulting a lot of papers on high-temperature superconductivity, I am most puzzled What is the specific mechanism? Although the existence of long-range magnetic order in iron-based superconductivity is considered to be one of the reasons for superconductivity, this is only a possibility, and it is only one of them."

Chen Xianhui nodded, "That's right, because there are many complex phase diagrams such as charge density wave, spin density wave, and long-range ferromagnetic antiferromagnetic superstructure in high-temperature superconductivity, so the study of its mechanism has always been very difficult, so this not only Not just your doubts, but the doubts of the entire academic community."

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

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

"What's even more amazing is that the isotope exchange in this system has the same effect on the critical temperature and the spin density wave transition temperature. Does this mean that the electron-phonon interaction plays a certain role in superconductivity in this system?"

"Hahaha." Chen Xianhui laughed loudly after listening to Wu Bin's question, "No wonder Professor Liu told me not to believe what you said. "

"The fact that you can ask this question means that you are not at all as familiar with superconductivity as you said, and you are just getting started."

"Ah? Is that what Professor Liu said about me?" Wu Bin's expression was slightly embarrassed. These days, people who speak cautiously will be criticized.

Seeing Wu Bin's embarrassing expression, Academician Chen Xianhui waved his hands and said, "It's a good thing to be in awe 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 raised, this is actually not just a simple electron-phonon interaction mechanism. There may also be coupling between spin and phonons..."

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

……

Outside the defense room, Jin Yunxia was waiting anxiously. From time to time, she grabbed Wu Shiqiang beside her and whispered, "Why hasn't this come out yet? Didn't my son just say that it won't take much time? Is there something wrong?"

Because Director Jiang told Wu Bin that the school would hold a graduation ceremony for him as soon as his graduation defense was over, so Wu Bin simply let his parents live next to the school for two days, and went back after attending the graduation ceremony.

After Jin Yunxia heard the news that Wu Bin was going to defend his graduation defense today, she wanted to come together no matter what, so she waited at the door of the defense room.

After hearing this, Wu Shiqiang patted her on the back and said, "Oh, don't worry, if your son says there is no problem, he will be fine, just trust him."

"That being said...but it's been too long."

At this time, Li Yan, who was also waiting on the sidelines, said with a smile: "Don't worry, auntie, this kind of defense, after a long time, it can only show that they have a lot to talk about, and the defense tutor will not think about dissatisfied students." Talk to them a lot."

After hearing this, Jin Yunxia patted her chest and said, "Then I'm relieved, thank you, little classmate, I remember your name is... Li Yan, right?"

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

"Thank you for taking good care of my son at school, and for coming here to wait for his reply."

"Auntie, it's your son who takes care of me. He has helped me a lot. I'm his first follower."

"Oh, you can't say that. It's right for classmates to help each other. There's no such thing as a follower." Jin Yunxia smiled and waved her hands, then looked at Lin Ziqi who had been standing beside Li Yan and said: "That... ...Auntie has a bad memory, have we met this classmate somewhere?"

Lin Ziqi, who was asked, immediately stood up straight and nodded, "Yes! We met at the entrance of the library when you came to visit Wu Bin last summer, auntie."

"Oh~~ Yes, I remembered." Jin Yunxia patted herself on the forehead: "Look at my memory, but you seem to be different from then?"

Lin Ziqi lowered her head and said, "Probably because I was wearing glasses at that time."

"Yes, yes, yes." After speaking, Jin Yunxia leaned closer to Lin Ziqi and took a look: "It's better not to wear glasses, what a pretty little girl."

"Thank...thank you, Auntie." Lin Ziqi thanked her with a blushing face.

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

Lin Ziqi quickly waved her hands and said, "You're welcome, you're welcome."

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

Looking at the people waiting outside the door, Wu Bin smiled and said, "Everyone, I've graduated."

Only now did Jin Yunxia completely let go of her hanging heart, and excitedly went up to give Wu Bin a hug, and then bowed to Professor Chen Xianhui, "Thank you, teacher, thank you, teacher."

Chen Xianhui quickly supported Jin Yunxia and said, "You don't need to thank me. Your son is 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 happily.

PS: I found out that it happened to be Chapter 300~ Sahua
(End of this chapter)