The top student must be diligent.

Chapter 160 Praise God Xiao!

Xiao Yi's idea was not a sudden one.

Before coming here, he actually knew something about the subject, but had a rough idea of ​​the research progress of Academician Pang and his colleagues.

Naturally, we also know the process involving the transformation of the parent compound and the parent-superconductor.

So in his early research, he thought about what method should be used to achieve an FeSe monolayer with ordered iron vacancies.

Then, hydrogen, the smallest atom of all elements, came into his sight.

"Professor Guo, next I'll need you to simulate this process to see if it can be implemented on a computer."

Finally, a feasible direction was found, and Pang Cheng turned to Guo Ding and said.

If relatively positive results can be obtained through computational simulation, then this method will definitely have great potential.

Guo Ding came back to his senses at this time, and nodded: "Okay, leave it to me, but..."

He turned his head and glanced at Xiao Yi again, and said: "Of course I also need Xiao Yi's help, and I need you to explain the details to me."

Xiao Yi smiled and said, "Of course."

Pang Cheng nodded, then patted Xiao Yi on the shoulder, "I'll wait for your good news."

Academician Pang left, but seeing that he quickened his pace slightly, I guess he was thinking about the specific implementation method of this experiment.

Only Xiao Yi and Guo Ding were left again.

Guo Ding blinked and said to Xiao Yi: "You are really... really surprising."

Xiao Yi said modestly: "I was just thinking about it casually."

Guo Ding was helpless, "Then you are really casual enough."

Shaking his head, Guo Ding said no more. Anyway, he had a clear idea of ​​his own positioning, which was to understand the field of computational physics.
Then he stopped talking nonsense: "Then let's get started now. Regarding this hydrogen power method you mentioned, what is the specific implementation principle?"

Xiao Yi nodded and began to introduce.

"First, we need to clarify our goal, which is to introduce iron vacancy defects into FeSe/SrTiO3 monolayer superconductors."

"What we need to know is that in order to introduce an iron vacancy defect, we have to overcome the migration energy barrier."

"Take the migration of Fe atoms in FeSe crystals as an example. If Fe atoms migrate from one lattice position to an adjacent position without the help of other auxiliary means, the energy barrier that needs to be overcome is relatively strong. It is also difficult to achieve this under experimental conditions. Even if we use the energy input method, it is difficult for us to ensure the uniformity of energy input."

"So we have to find a way to lower the migration energy barrier."

"At this point, we can easily think of using other atoms to weaken the metal bond, and obviously, we can think of the hydrogen bond of hydrogen atoms."

"When hydrogen atoms combine with metal atoms, they cause a redistribution of the electron cloud. This redistribution can change the local charge density around the metal atoms, thereby changing the local potential energy surface, and the Fe-Se bond is weakened."

"Another advantage of hydrogen atoms is that they are small enough to diffuse quickly through the material."

When Xiao Yi said this, Guo Ding's eyes lit up: "Oh! I understand!"

Although he was only a computational physicist, he was not unfamiliar with the basic knowledge. Therefore, after Xiao Yi's detailed explanation, he quickly understood the basic principles of this experiment.

"Amazing!"

He gave a thumbs up and praised.

"Many people have studied this topic over the years, but no one has thought of using hydrogen atoms to achieve this."

Then he took out a piece of draft paper and started writing on it, "Well... Next, let me build a model of this process and then run it on the computer."

“I feel like it’s totally feasible.”

"Well……"

Without wasting time, Guo Ding immediately began to build a model of the experimental process based on the principles.

Xiao Yi was also watching from the side. Although he did not do it himself, this did not prevent him from roughly understanding Guo Ding's modeling process.

There is not much gap between computational materials science and computational physics, not to mention that what they are studying now is closely related to materials science.

In this way, time passed quickly, they completed the modeling during the day, and started running it on the computer at night.

As a national research center, there is certainly no shortage of servers here, and even supercomputers are available.

Finally, the simulation results came out.

"It worked! We actually introduced an iron vacancy defect!"

In front of the computer, Guo Ding waved his fist excitedly and looked at the results on the computer, feeling very excited.

This key problem was successfully solved by them!

"Good for you!"

He glanced at Xiao Yi next to him and laughed.

Xiao Yi smiled, but he was not too happy.

For Guo Ding and others, this problem may have stumped them for a long time, but for Xiao Yi, this problem was solved on the first day he arrived.

Ok……

It's not really a high sense of accomplishment.

He said calmly: "We still have to simulate the appropriate environment."

"For example, the hydrogen environment, hydrogen concentration, pressure and temperature are all key parameters."

“And then there’s the time for heat treatment.”

Guo Ding smiled and nodded: "Of course, I will set the parameters later and run it overnight to see if I can find the best temperature range."

"By the way, we have to tell Academician Pang the good news."

It was already 10 o'clock in the evening, so there were only two of them left here.

Guo Ding then took out his cell phone and started making a call, while smiling and saying, "I don't know if he has slept yet. It's better that he hasn't, otherwise he won't be able to sleep tonight."

The call came through quickly.

Pang Cheng's slightly expectant voice came from inside: "Professor Guo, is there any good news?"

Guo Ding shrugged helplessly at Xiao Yi, "Well, it seems he is not asleep."

Xiao Yi laughed and shook his head.

"Yes, good news. Following Xiao Yi's idea, we successfully introduced the iron vacancy defect, and the simulation results also observed the transition from the superconducting phase to the insulating mother phase!"

Pang Cheng immediately burst into laughter: "Good! Good! Good!"

"Xiao Yi should be right next to you. Please thank him for me! I will notify the others to hold a team meeting tomorrow morning and tell them the news."

Guo Ding nodded: "No problem."

Soon, they hung up the phone, and Guo Ding smiled at Xiao Yi, "You heard it too, Academician Pang is very grateful to you."

Of course Xiao Yi heard it and nodded with a smile.

"OK, then our work is done. Let's have a good sleep tonight. Tomorrow is their experimental task, which has basically nothing to do with us. Um...but we have to see if we can run the best experimental conditions tomorrow morning, so we have to come early tomorrow morning."

Then, Guo Ding set up a program on his computer to find the best conditions and started running it.

"Okay, let's go."

……

Silent all night.

The next day, it was 9: in the morning.

In the conference room, most of the other members of Academician Pang’s research group have arrived.

However, there was still some confusion on their faces.

At around ten o'clock last night, Academician Pang suddenly sent a notice in their group chat, saying that a group meeting would be held this morning and asked all of them to be present on time.

"Didn't we have a group meeting four days ago? Why is it held again today? Do you know what's going on?"

The graduate students in the group began to discuss the matter. The relationships between young people were relatively close.

"I'm not going there!" "I'm not going there either!"

Finally, all the graduate students looked at their senior brother Xu Zhiqiang and asked, "Senior brother, do you know what's going on?"

At this time, Xu Zhiqiang yawned deeply, and at the same time, he clapped his hands on his mouth, making an "ah~ah~ah~" sound.

Seeing that his fellow apprentices had seen him, he looked confused and asked, "What happened?"

The fellow students immediately shook their heads and sighed.

Sure enough, they shouldn't have counted on this senior brother.

At this time, Xu Zhiqiang realized that this was somewhat embarrassing for his position as the senior brother.

At least, in the question on Bihu that he read yesterday, although the other senior brothers did not understand the topics, could not do the experiments, and had no papers, they were at least well-informed and had many options.

No, he can't go on like this. He is good for nothing except money.

So he observed the people at the scene, and finally analyzed calmly and thought carefully. His eyes lit up and he said, "Ahem, look, who are missing from our room?"

A junior fellow student said, "Teacher Pang hasn't arrived yet, and there's also Professor Guo, um... and God Xiao?"

"Right!" Xu Zhiqiang clapped his hands, and then said: "Think about the lab last night. We all left. Who else stayed?"

"Uh... isn't it just Xiao Shen and Professor Guo?"

Xu Zhiqiang nodded, and then said: "So, maybe Xiao Shen and Professor Guo have come up with something that is worth our boss Pang to set up a special group for us to discuss."

But at this time, a voice came from the side.

"Then you may be overthinking it. It's only Xiao Yi's first day here. It's enough for him to figure out what our research topic is and what results can we get?"

The person who spoke was Cui Yuanhao. It was obvious that although he was taught a lesson by Academician Pang yesterday, he felt even more dissatisfied.

However, Xu Zhiqiang frowned.

Damn, doesn’t he know that he is now trying to establish his own prestige in front of his fellow junior brothers and sisters?
What did this guy say when he came over?

Although the other party is a full researcher and an outstanding young scholar, Xu Zhiqiang is not afraid.

As the old saying goes, as long as I am cool enough, no one can influence me.

What's more, Xu Zhiqiang's mentor is Academician Pang, not Cui Yuanhao. Why would he be afraid of a beating?

He immediately made a sarcastic remark: "Why are you arguing with a student like that? Although he has been selected as an outstanding young scholar and you haven't, you are older than him! Look, you are already 40 years old and he is only 18."

Xu Zhiqiang's words immediately made Cui Yuanhao's eyes widen.
How dare you, a person who has been studying for a PhD for 6 years, talk to me like this?

He pointed at Xu Zhiqiang and was about to speak: "You..."

But Xu Zhiqiang didn't give him a chance to speak, and continued: "You didn't listen to what Lao Pang said to you yesterday, right? Do you want me to repeat it to you again? You haven't been selected as an outstanding young scholar yet, so think about your own problems, and don't leave it here..."

But at this moment, Academician Pang's deep voice came from the door: "Who are you calling Lao Pang?"

Xu Zhiqiang's eyes suddenly widened and he looked towards the door, and saw Academician Pang walked in, followed by Xiao Yi and Guo Ding.

Xu Zhiqiang said quickly: "I'm not, I didn't, teacher, please listen to my excuses... Oh no, listen to my explanation!"

Pang Cheng came up and pinched his ear again, pulling him up: "You stand and listen to this group meeting."

Xu Zhiqiang's fellow junior and senior students immediately looked at him with sympathy, and of course some of them were gloating.

However, Pang Cheng did not forget to turn around, glare at Cui Yunhao again, and point at him warningly.

Afterwards, he sat in the front and said, "This group meeting will be mainly given by Xiao Yi and Professor Guo."

Finally, they talked about good news, and Pang Cheng smiled: "Yesterday, Xiao Yi proposed an experiment called the hydrogen power method, which can help us introduce iron vacancy defects in FeSe/SrTiO3 monolayer superconductors."

"In this group meeting, Xiao Yi will first explain to you what this hydrogen power method means, and then Professor Guo will show you the simulation results."

“After the group meeting, we officially started the experiment. Based on the simulation situation, we found the best conditions through experiments, and then conducted observations and analysis.”

"Xiao Yi, I'll trouble you first."

Pang Cheng said to Xiao Yi with a smile.

Xiao Yi nodded, then walked to the front and began to introduce this hydrogen power method to the people present.

The other people in the conference room all showed shocked expressions.

What the hell?

It was only Xiao Yi’s first day here yesterday, and he has really achieved some results?
really?
Xu Zhiqiang, who was rubbing his ears at this time, stopped rubbing his ears and was stunned.

Ah this?

Are you serious?
At this time, his fellow junior brothers and sisters all looked at him with admiration.

He really is worthy of being their eldest senior brother, he actually has news.

Xu Zhiqiang noticed these gazes, was stunned at first, then quickly restrained his expression, at least not to look shocked.
But he still couldn't help but glance at Xiao Yi.

Not bro...

Are you sure you didn't open it?

But at this time, he glanced at Cui Yuanhao who was sitting on the other side.

At this time, Professor Cui also looked incredulous. How could someone be able to make progress on the first day?

According to what Academician Pang said just now, Xiao Yi's method may even be able to solve the key problem that has been bothering their research group for so long?
Xu Zhiqiang raised his eyebrows.

Hey, what a bad luck! Now you know what Xiao Yi is capable of, right?

Are you powerful, Brother Xiao?
Xiao Yi on the stage didn't know what had just happened in the laboratory. At this moment, he was also explaining the hydrogen power method.

It was easy to explain, and soon everyone present understood the details of this method, even Xu Zhiqiang understood it.

For a moment, their eyes lit up.

The principle is easy to understand, but being able to figure it out is the key.

Such a clever method is not something they can easily figure out.

Afterwards, Guo Ding showed them the data simulated on the computer, which made everyone in the conference room look surprised.

From this perspective, the problems they are currently facing really have a chance of being solved!
Pang Cheng did not waste any time. After finishing the introduction, he took people directly back to the laboratory and started conducting experiments according to the experimental methods given by Xiao Yi.

In the first step, a high-quality FeSe/SrTiO superconducting single-layer sample is prepared and then placed in an environment containing hydrogen.
This morning, the computer had already run out several suitable environmental parameters, so their first experiment was to set up the hydrogen environment directly based on those calculated parameters.

The second step is heat treatment. The injected hydrogen needs to be decomposed into two hydrogen atoms under high temperature conditions so that they can diffuse into the sample material and interact with the iron atoms inside it.

In a hydrogen environment, iron atoms are more likely to break away from their original positions, migrate to new positions or leave the film surface, thereby forming vacancies at their original positions.

The third step, of course, is to observe whether vacancies are formed, which requires real-time observation using a scanning tunneling microscope (STM).

Just like that, after a day of experiments, cheers finally broke out in the laboratory.

“Success! Iron vacancy defects were generated on the sample surface!”

Looking at the images on the scanning tunneling microscopy spectrum, everyone showed joy on their faces.

This basically means that the most difficult step in the entire subject has been taken!
"well done!"

Pang Cheng also smiled, turned around and patted Xiao Yi on the shoulder, saying with a smile: "Thanks to your method! This method alone is more than enough to publish a top article. If we complete our experiment, there will be no problem publishing PRL. It depends on your choice. If you are willing to publish this experimental method together with our final results, I can give you the first authorship."

Xiao Yi certainly did not choose to publish it separately. To him, the value of publishing it separately was not that high. It would be better to publish it in PRL. However, there was another key point. He did not really care about these things. So he said, "Let's publish them together. If we publish them separately, I still have to write the paper myself."

Pang Cheng immediately burst into laughter: "Okay! Let's send them together!"

Then he turned to look at the others and said, "Okay, let's not rest and continue the experiment."

Finding a method to introduce iron vacancy defects is only the first step. Next, they need to find the most suitable conditions to introduce more defects into the sample. After that, they need to observe the transition process from the superconducting phase to the insulating parent phase by cooling. Only in this way can they achieve their main goal - analyzing the principles of high-temperature superconductivity.

Thinking of this, they suddenly became full of energy, which was much better than the previous state of stagnation due to being stuck on problems.

And all this was brought by Xiao Yi.

Praise God Xiao!

(End of this chapter)