Chapter 225 I have some new ideas Xu Qingzhou first went to the dormitory to rest for half an hour, and arrived at the laboratory at 1:50, where he met the laboratory director, Academician Ma Liangzai, and another person, Professor Chang. Academician Ma Liangzai looked at Xu Qingzhou and was a little surprised: "You are so young, it's a bit scary, Old Chang, we are still studying hard at this time." "Yes, Xiao Xu was poached from the School of Mathematics by Director Ji and his team," said Professor Chang. Xu Qingzhou smiled and said, "You are too kind. I still need to learn more from you seniors." Professor Chang said: "Xiao Xu, your experiment is very meaningful. Based on your theoretical model of the influence of spatial walk-off effect on compression, we have made subtle adjustments to the signal source." "Currently, the stability of the signal channel has been improved by a full ." "I'm glad I can help." Xu Qingzhou said that it was similar to his original estimate, . In such a large-scale experiment, even could have a decisive impact. Professor Chang asked: "Xiao Qi has told you about the mission, right?" "Well, as I said, I'll talk to Professor Zhong first."
Professor Chang nodded and said, "You should follow Professor Zhong first. Judging from those papers, matrices and linear algebra happen to be your areas of expertise. As for other experiments, we can talk about them after you are familiar with the project." The Physics Department of Peking University has been a bit disappointing in recent years, but it is different now. He sees hope in Xu Qingzhou, so he wants to let Xu Qingzhou get involved in more experiments if there is a chance, so that he can accumulate experience in advance. "Okay, thank you Professor Chang." Xu Qingzhou nodded with a smile. Academician Ma and Professor Chang encouraged Xu Qingzhou and then called everyone out for a meeting. There is no empty talk in this kind of meeting. It basically summarizes the experimental situation of the previous week, points out the shortcomings in the experiment, or arranges the next experimental schedule. There are a total of 16 people in the entire laboratory, and including these interns, there are 19 people in total. Academician Ma is the overall person in charge, followed by Professor Chang. Xu Qingzhou was not unfamiliar with the various professional terms used by Academician Ma and Professor Chang. He has presided over the development of several quantum satellites and is very familiar with orbital parameters and quantum states. Of course, there were also differences. For example, the quantum satellite development technology was relatively mature at that time, and the satellites launched were basically medium and high orbit satellites. However, no matter how things change, the essence remains the same. We are now in the stage of expanding our territory. For low-orbit satellites, the difficulty of alignment and tracking between the satellite and the ground increases sharply, and very little quantum information is received. The group that Xu Qingzhou belongs to is mainly responsible for providing computing power support. There are 5 people in it, including Professor Zhong Yongtao, 2 doctors, Xu Qingzhou and Deng Ziyi. Current work content: responsible for designing mathematical models and algorithms for quantum states and entangled states. This model will be combined with the previously completed attitude control model, free space loss model, etc. to form a complete model system. After the work meeting, everyone quickly got back to work. The task of Professor Zhong's group during this period is to create a mathematical model of the quantum state. Quantum states are usually represented in quantum mechanics as a linear combination of complex vectors that exist in an abstract mathematical space called a Hilbert space.
Professor Zhong led Xu Qingzhou and Deng Ziyi to be responsible for the complex vector representation in the model, and the other two were responsible for the design of the density matrix representation. Next to the computing classroom. "The mathematical model of quantum states allows the state vector to be expressed as a linear combination of basis vectors. Ours will be more complex and will build a more efficient and advanced model based on this," Professor Zhong told Xu Qingzhou and Deng Ziyi. "This is the basic framework I built last night. c1, c2, ..., cn are complex coefficients, representing the weight of each ground state in the total state. The square norm of these coefficients (|c_i|^2) represents the probability of the corresponding ground state being measured." Xu Qingzhou thought in his mind that Professor Zhong’s basic direction was correct, but some individual places could be optimized. For example, the third small point in the second part could increase the dimension of the Hilbert space, expanding it from the traditional three-dimensional Hilbert space to the four-dimensional Hilbert space of multiple quantum bits. Professor Zhong said so much that Deng Ziyi beside him could hardly keep up. While trying her best to remember, she glanced at Xu Qingzhou beside her and saw that his eyes were blank, almost the same as hers, and she felt relieved. Call ~ I hope this Junior Brother Xu is just like me. Although he is good at mathematics and has published two SCI papers in the field of physics, it is not easy to keep up with such large-scale experiments. Professor Zhong and his colleagues' thoughts jump too quickly. Although she has been here for a month, she has just adapted to the busy life here. It feels like a level 1 hero who has just entered the novice village and is dragged by teammates to fight a level 1 boss. But it's too difficult. It’s not terrible if you can’t keep up, what’s terrible is that you are the only one who can’t keep up. On this side, Professor Zhong wrote down the formula on the blackboard while speaking. "[|\psi\rangle = c_1|\psi_1\rangle + c_2|\psi_2\rangle +\cdots + c_n|\psi_n\rangle " In fact, he didn't have very high requirements for these two interns. The big experiment will be carried out in December. Now it is May, and it seems that there are still six or seven months in between, but there are so many things to do. In addition to the model, a large number of reception tests need to be carried out continuously. Time is very tight. It would be better to have more people to help with chores and organize the data. Moreover, this student Xu Qingzhou can be said to be a mathematics "expert" who specializes in the field of prime numbers, but he also seems to be good at linear algebra and function analysis. Once he gets used to it, he will definitely be able to play a significant role. "Okay, this is the general framework. Xiao Xu, you will be responsible for calculating the value of the diagonalized Hamiltonian H. Xiao Deng, you will organize the data files over there and classify them like before." Professor Zhong assigned tasks to the two people. "okay." Deng Ziyi had no objection. This junior fellow student was definitely better than her in math, so it was reasonable for her to do some odd jobs. However, seeing Xu Qingzhou still in a daze, she secretly shook her head, thinking that this junior fellow's acting skills were not good enough. The professor had already finished speaking, but he was still pretending. Just as she was about to pull his sleeve, she heard Xu Qingzhou say: "Professor Zhong, I have a new idea." Professor Zhong was stunned for a moment: "You go ahead." "In this part, we can give a quantum system's Hamiltonian H and initial state ψ(0), and then use the matrix indexation method of the numerical method time evolution operator to solve the Schrödinger equation and obtain the quantum state ψ(t) at any time t." Xu Qingzhou circled part of the content on the blackboard and wrote another formula next to it: 【i\hbar \frac{\partial \psi(t)}{\partial t}= H \psi(t)itψ(t)=Hψ(t)】
Professor Zhong looked at the blackboard and fell into deep thought. At first glance, the method and steps used by Xu Qingzhou seemed to be more efficient than what he had just said. Deng Ziyi was stunned, with a confused expression, and there was only one thought in her mind: Who am I and where am I? What is this ghost? What kind of hero can defeat a level 20 monster right at the start? (End of this chapter)