When the students present knew that the topic he was going to talk about was related to quantum mechanics, a large number of liberal arts students were stunned for a while, because they knew that as long as quantum mechanics was involved, they would definitely be dismissed from the series, which was too difficult to understand.
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Perhaps the most familiar thing for liberal arts students about quantum mechanics is the "Schrödinger's cat" that is both dead and alive. Then, after a moment of confusion, he discovered that it can exist in two states at the same time, dead and alive.
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This speech was also broadcast live on the school forum, and naughty comments have already begun to "disturbing" it.
On the other hand, the men in science and engineering present were in high spirits, especially the students who specialized in computer science. They were as steady as old dogs and expressed no pressure at all.
On the stage, Ye Hua spoke eloquently:
"...We are currently doing research on superconducting technology applied to computers, called the Josephson junction. As you can tell from the name, Josephson is a pioneer. It is amazing. Superconductivity itself is amazing. I will try my best to explain it.
To make it easier to understand, what is superconductivity? Everyone should know that, simply put, there is no resistance. Superconductivity was discovered by humans more than a hundred years ago. It must be a quantum effect at the microscopic level, because
This phenomenon will not occur at the macro level."
"The cbs microscopic theory of superconductivity... In order to take care of other non-professional students, we will not delve into what this cbs is. It says that the formation of superconductivity is the formation of two electrons in a metal. These two
The electrons have opposite spins and momentum to each other. They can move without loss in the crystal lattice, so there is superconducting current. On this basis, people have begun to conduct further research. Of course, we also have a scientific research team doing in-depth research."
"Someone has discovered that under certain special circumstances, superconductors can pass current even if there is no voltage. This is not difficult to understand because there is no resistance, but how is it formed?"
"The two superconductors are connected by a very thin material. This material can be an insulator, a normal conductor, or a weakened superconductor. For example, a certain section in the middle is made thinner. In these three cases
As long as the current passes through the superconductor, there is no need to continue to apply voltage, and the current will continue to flow through the device. This is the so-called Josephson junction."
"You may be wondering, how can you continue to conduct electricity after being insulated? Hey! It's just that. The quantum world is so magical. In the terminology of the industry, this is called the quantum tunneling effect, also called the quantum tunneling effect.
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"For a quantum, even if there is a hard and dense wall in front of it, it can still pass through it with a very high probability. This is the best explanation for the fact that there is no airtight wall, which is quantum tunneling."
"This effect is very important. Without the quantum tunneling effect, the earth would probably not have the conditions for the birth of life, because the sun would not be so hot, and the radiation from the sun's interior reaches the outside through the quantum tunneling effect."
"It is worth mentioning that the scientist Josephson once again made outstanding contributions. He was rather strange in his later years, probably middle-aged. Ever since he saw Bell's inequality, he felt that quantum entanglement was a ghostly phenomenon at a distance.
The effect was so miraculous that he was obsessed with it and couldn't extricate himself. From then on, he began to study telepathy and mind control these magical things."
"Physicists at the time felt that this smart mind had been ruined by physics, which was really a pity."
"When the precision of traditional chips has reached its extreme, Moore's Law has expired, and the semiconductor industry has stagnated. People firmly believe that the next breakthrough is quantum chips and quantum computers."
"So about quantum computers, this is a long story and involves a lot of professional knowledge. Here I will briefly talk about the standards set by the scholar Divinson for quantum computers, which is the so-called Divinson.
Sen standards, it is said that to realize a quantum computer, five standards must be met at the same time, which five standards?"
“The first one: have qubits that can be well characterized and are scalable.”
"Scalability means that it can be integrated. Of course we are all familiar with integrated circuits, and good characterization, in computer terms, means that each qubit must be individually addressable, which is very important."
"Rule 2: There must be a way to set all qubits to 0 before calculation."
"That is, initialization. This is easy to say but very difficult to do. Current technology basically operates on each qubit individually, because there are few, but the problem is what happens when there are more? How do you do one-click initialization?
?There is currently no solution. Once the problem is found, solving the problem is the subject of our scientific research department."
"Article 3: There must be a universal set of quantum logic gates."
"What does it mean? We know that in classical computers, the state of a transistor is used to represent 1 or 0. How is this state implemented? It is the high and low level, and then the operation is performed through a series of logic gates. The logic gate is
Transistors, through special arrangements, can perform logical operations."
"For example, if two high levels come over, it represents two 1's, and then passes through an AND gate, and finally outputs a high level, which represents 1. Then the overall process is true (1) and true (1) =
True(1).”
"Why does the computer generate heat? Because my original two bits of information 1 turned into one bit of information after passing through the AND gate, and one bit was lost, so heat was generated."
"Note that the generation of heat is related to the loss of information, and it is a direct cause. It is not necessarily related to whether the process is reversible. What do you mean?"
"For example, in the example just now, there is a question, or there are two levels coming through, but I don't know the level. After passing through an AND gate, a 1 is output. So what is the information of the two inputs?"
"By outputting 1 through the AND gate, you can only input two 1's, so you can easily deduce the answer to this process, so it is reversible."
"But why is it said that the AND gate is still an irreversible gate?"
"Just change it. For example, if two inputs are input and the output result of the AND gate is 0, what are the inputs? It may be all 0, it may be 1 at the top and 0 at the bottom, or it may be 0 at the top and 0 at the bottom.
1, so you will find that if it cannot be determined, it cannot be clearly mapped back to the input one-to-one, and the situation is irreversible."
"But the 'NOT' gate is different. As long as you tell me the output, no matter what it is, I know that the input is opposite to the output, so the AND gate is an irreversible gate and the NOT gate is a reversible gate."
"Then what are the characteristics of a reversible door? It means that as much as you input, I will output it. No information is lost, so no heat is generated during the computer process."
"Some students may be questioning it, saying, how could the NOT gate not produce heat? How could passing electric current not produce heat? Could it be that I am taking a fake physics class?"
A large group of liberal arts students in the audience were bewildered and laughed together, many of them looked confused, and some girls didn't care whether they understood or not, they just came to see what their idol said.
"Of course everyone is learning physics correctly, but please note that what I am talking about here is that no heat is generated due to the loss of information during the calculation process, and the heat generated by the loss of information is the main source of heat generated by the CPU. So we
I found that as long as I use the computer, the CPU will get hotter and hotter when a large amount of information is transmitted, and this is the reason."
Non-major students, and most liberal arts students, suddenly had a look on their faces. Computers are used by everyone, and they are familiar electronic products. It is common knowledge to know that the computer's CPU will heat up, but why does it heat up? The reason is not
Many people don't know, but now they know after Ye Hua said this.
"Then can the irreversible gates in classical computers be turned into reversible gates? Some people have actually proposed several solutions in theory. For example, one is to change the input and output of the logic gate to three, and then
For example, a kind of logical operation is called XOR operation, and the corresponding one is the XOR gate, and binary addition is completed through it."
"The XOR gate and the AND gate can form a half adder. The reversible version of the XOR gate is called a controlled NOT gate. A very important quantum logic gate in quantum algorithms is the two-qubit controlled NOT gate. But please note
One thing, this is achieved through quantum entanglement, not through traditional circuits."
"Then quantum computers are all quantum, not transistors, so there is no circuit."
"Article 4: There must be an effective way to solve the decoherence problem."
"That is the principle of quantum coding."
"The last one: You must be able to get the desired information answer by measuring qubits."
"This hides a so-called efficiency problem. The famous quantum Shor algorithm can achieve that the desired results in the measurement are coherent and constructive, and the unwanted results are coherent and destructive. But the process requires repeated measurements to obtain it. Change
In other words, the more times you measure, the more accurate the results will be, but theoretically you cannot give a 100% correct answer, you can only get infinitely close, so is there a better way to get the answer by calculating the qubits?"
"This is the research direction that our team is focusing on, and it is also a major mystery that research institutions or teams in the industry around the world are trying to uncover."
"So far, there is no machine in the world that can perfectly meet the above five criteria at the same time, so the research on quantum computers has a long way to go."
On the stage, towards the end, Ye Hua looked at the audience and couldn't help but laugh to himself: "Well, I think today's speech is the most failed one I have ever given, because a large number of people below were drowsy after listening to it.
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Suddenly, the whole audience burst into laughter. The science and engineering students said that they felt no pressure to listen. If there were liberal arts students nearby who felt inexplicably proud, they would swell.
Ye Hua on the stage continued: "Anyway, I prefer to label myself as a scientific and technological worker and be proud of it. Today's speech can be regarded as an easy-to-understand popular science speech. In fact, I think technology
In addition to immersing ourselves in research, workers or scientists also have the obligation to popularize science for the general public."
"Our country's science popularization work is not good enough. I saw some articles about science on the Internet, and when I pulled them to the comment area, I saw comments that I clicked in and then left in confusion."
There was another burst of laughter, and Ye Hua said: "This has led to a very bad phenomenon. Science gives the public the feeling that it has nothing to do with them. It is so remote and mysterious. That's why there are so many confused people.
Leave a comment when you leave.”
"I think this is very detrimental to cultivating the scientific interest and hobbies of the general public. In fact, science is very simple, interesting and wonderful. Only when you understand it can you discover its beauty. It is not mysterious, because you
Of course it’s mysterious if you don’t understand it. But once you understand it, it’s actually the same thing. Science is a process of seeking truth.”
"In general, this is a popular science speech, talking about the world's most cutting-edge and popular superconducting technologies, quantum computers, etc. Due to time constraints, we can only talk about it here."
"Superconducting technology is one of the most popular technologies among the many technologies of quantum computers. The research of quantum computers has a long way to go, but if we follow the historical rules of the past, a von Neumann should be almost there by this time.
A genius like Dirac in the scientific world opens a door for everyone. I am very much looking forward to the birth of this genius. Maybe he is one of the students here. Who knows? We must know that our FNU has produced many quantum products.
Top students in the field, such as Mr. Zhang Shousheng."
"But I think it's time for such a new god-level figure to appear. Let's wait and see."
