Starting from a top student and marching towards the sea of ​​stars

Chapter 147 Don’t use experimental equipment as an excuse
Originally, Qi Wan thought that it was impossible for Ning Chen to measure a qualified three-dimensional structure diagram immediately when he used STM for the first time.

When Qi Wan came into contact with STM for the first time, she practiced for several hours before she finally found the operating feel.

"Well, I can swear to the lamp, this is really my first time using STM." Ning Chen said with a smile.

Although Qi Wan was still a little dissatisfied at this time, she thought that Ning Chen did not study physics, and it was indeed unlikely that she had been exposed to STM before.

"Okay, I believe you. Now that you have learned how to operate it, let's start the experiment."

……

In the following days, in addition to attending lectures, Ning Chen would come to Ren Mingshan's laboratory almost every day to participate in research projects on the surface states of topological insulators.

After a long period of contact, Ning Chen discovered that Qi Wan did have strong professional abilities.

Although Qi Wan looks like a child on the surface, he is methodical when conducting experiments and has some unique ideas of his own.

This made Ning Chen and Qi Wan very efficient when conducting experiments together, and their subject experience increased rapidly.

It's just that Qi Wan's personality is a bit arrogant, which is in sharp contrast to Song Xiyun's mature intellectuality.

Ning Chen doesn't really like girls with this kind of personality, but when it comes to a 19-year-old physics genius girl, Ning Chen thinks it's still acceptable.

On this day, Ren Mingshan came to the laboratory to learn about Ning Chen's situation and the progress of the experiment.

"Ning Chen, how are you feeling recently? Have you adapted to the laboratory environment?"

"Well, I think I'm quite adaptable. Qi Wan has taught me a lot, and I can participate in some experiments."

After hearing Ning Chen's words, Qi Wan said:
"Teacher Ren, Ning Chen learns things very quickly. He memorized all the knowledge once I explained it to him."

Ren Mingshan also smiled when he heard this:
"How else could Ning Chen publish so many papers in Nature at such a young age? Qi Wan, you should also learn more from Ning Chen, and don't always think that you are the best."

Qi Wan pouted slightly, and it could be seen that she was still a little dissatisfied, but she immediately agreed obediently:
"Okay, Teacher Ren, I will learn more from Ning Chen."

After chatting with Ning Chen and Qi Wan for a while, Ren Mingshan checked the progress of their recent experiments.

After reading their recent experimental data and the data analysis process, Ren Mingshan frowned slightly, as if there was something that did not satisfy Ren Mingshan.

"Qi Wan, with the surface morphology information of the sample we have obtained now, can we obtain the electronic standing wave of the surface state of a topological insulator?"

Upon hearing this question, Qi Wan replied in a low voice:

"Teacher Ren, it's not possible yet. Our scanning tunneling microscope has not yet reached such accuracy."

Ning Chen also knows that this problem exists, although the scanning tunneling microscope can perform atomic-level imaging of the sample surface in real space.

However, it cannot give information about the material in the reciprocal space, and this problem has not been solved yet.

Ren Mingshan was obviously not satisfied with Qi Wan's answer and said seriously:

"So, is it a problem with the instrument? The scanning tunneling microscope in our Yanda laboratory is the most advanced in the world. I can't build you a new scanning tunneling microscope just for this subject. Bar?"

Being criticized like this by Ren Mingshan, Qi Wan's face immediately turned bad.

"Teacher Ren, I will continue to think of other ways."

Ren Mingshan also knows that Qi Wan is only a 19-year-old girl after all, and his words are enough to this extent.

"Well, this is the correct attitude towards scientific research. Our previous scientific research environment was far less good than it is now, and we have suffered far more hardships than you, but haven't we survived? Sometimes there are only so many things available. Since we can’t change external factors, we can only find solutions from other aspects.”

Qi Wan stopped talking and nodded like garlic, without making any refutation of Ren Mingshan's words.

It was also the first time for Ning Chen to see Ren Mingshan like this. In class, Ren Mingshan always gave people a very approachable feeling.

But facing his own student Qi Wan, Ren Mingshan was still very strict.

Ning Chen can also understand this situation. Many professors will appear very friendly during class, but the more they treat the students they teach, the more severe they will criticize.

It is very rare for teachers and students to get along like friends like Xu Zhou and Ning Chen.

Ning Chen knew that perhaps a certain amount of criticism would be more conducive to students' growth, but if Ning Chen had a choice, he would still like this way of getting along with Xu Zhou.After Ren Mingshan left, Qi Wan stopped pretending and his face immediately dropped.

Ning Chen could actually understand Qi Wan's current mood. If it were Ning Chen, although he wouldn't be as strong as Qi Wan, he would definitely not be very happy in his heart.

Qi Wan didn't say much throughout the morning, just silently conducting experiments, and all that arrogance and arrogance disappeared.

Ning Chen didn't bother to coax Qi Wan, and started thinking about the solution to this problem.

"Actually, what Qi Wan said is correct. With the precision of this scanning tunneling microscope, it is indeed difficult to directly observe the electron standing wave in the surface state of a topological insulator."

But Ning Chen couldn't directly move a more advanced instrument from the future, so he could only find other ways to solve this problem.

Ning Chen thought about it for a long time. Suddenly, Ning Chen really thought of a plan that he could try.

"If impurities or defects can be introduced on the surface of the sample, it may be possible to observe the electron standing waves in the surface states of topological insulators."

Ning Chen came up with this method because introducing impurities into the sample can cause defects, which can lead to elastic scattering of quasiparticles.

In this way, the eigenstates of different wave vectors on the same equal energy surface can be related to each other.

Thinking of this idea, Ning Chen did not rush to try it, but first deduced it on the draft paper.

Ning Chen used various relevant formulas to calculate various data of the incident wave after ejection. Finally, based on the wave vector, wavelength, period, momentum and other data of the ejection wave, he obtained the possible standing wave pattern of the ejection wave.

After completing the drawing of the standing wave pattern, Ning Chen felt more and more that his idea was feasible.

"In this case, even if the original scanning tunneling microscope is still used, the measurement results will be completely different."

In excitement, Ning Chen called Qi Wan over.

"Qi Wan, come here."

"What's the matter……"

Qi Wan still looked listless. Every time he was criticized by Ren Mingshan, Qi Wan had to recover the next day.

"Look at this."

Ning Chen didn't bother to explain it carefully to Qi Wan, so he directly handed his draft paper to Qi Wan.

After seeing the draft paper, Qi Wan's expression was indifferent at first, then his brows were furrowed, and his brain was racing.

After all, Qi Wan was not an ordinary student. After reading the contents on Ning Chen's draft paper, he quickly understood what Ning Chen wanted to express.

Qi Wan also took out the paper and started calculating by herself. After a few minutes, Qi Wan said excitedly:
"Yes, Ning Chen, your method is feasible! Maybe we can really use this crappy microscope to measure the electron standing waves in the surface states of topological insulators!"

Qi Wan swept away the gloom just now, and a smile began to appear on her baby-fat face again.

But listening to Qi Wan's words, Ning Chen also knew that Qi Wan still held a grudge against Ren Mingshan's criticism just now.

"Didn't you say before that the price of this microscope was 20 yuan? Why is it now a broken microscope?"

"Okay, okay, I just want to vent. Don't talk so much, let's verify it quickly."

The two of them took a look at the time and found that it was already noon, so they decided to go to the cafeteria to have a bite of food first, and then come back to continue the experiment.

After all, Ning Chen often loses track of time when doing experiments seriously. If he wants to maintain a long-term and continuous research state, he must still eat well.

Ning Chen and Qi Wan came to the cafeteria together. They each ordered a bowl of noodles. After a few minutes of eating, they returned to the laboratory to prepare for experiments.

Although the new experimental ideas have been determined, there are still many details that need to be finalized for specific implementation.

For example, if impurities are added to the sample, what specific impurities are added and the amount added.

If there is a structural defect, how to construct it, what is the scope of the defect, etc., these are all issues that need to be studied.

(End of this chapter)