Chapter 471

It's been mentioned before.

There are three theoretically feasible implementations of quantum computers.

One is a superconducting circuit, one is a semiconductor quantum chip, and the last is an ion trap.

Because Huaguo's work in this area started too late.

Therefore, in the two forms of superconducting circuit and ion trap, Huaguo is far behind the United States.

That's not just one or two positions, it's a distance of tens or hundreds of meters.

And in the direction of semiconductor quantum chips.

Because of the existence of Academician Guo, Huaguo can now be said to be standing on the same starting line as Mi Guo.

This is the only chance for China.

Using the implementation form of semiconductor quantum chips, quantum computers are developed.

If Huaguo wants to successfully develop the world's first quantum computer before the United States, this is the only way to go!

But let's be honest, it's not that easy to follow.

There are bound to be too many thorns and bumps along the way.

There is also the threat of an external strong enemy pressing forward step by step.

Even Academician Guo, who is the leader of the project team, has an attitude that is not optimistic.

But......

If you are not optimistic, you are not optimistic, since Academician Guo has taken over this task, he will definitely go all out.

After Academician Guo issued a convening order, nearly eighty percent of the high-quality talents in the field of quantum semiconductors across the country gathered here to participate in this research and development plan.

However, the appearance of Gu Lu was unexpected by Academician Guo.

For Gu Lu, a 'mathematician', Academician Guo originally planned to reject him.

Since Gu Lu is so smooth in the mathematical world, then just stay in the mathematical community honestly, come to our physics community to mix in the excitement, you are such an excellent mathematician to do physics projects, isn't it a huge loss for the mathematical community!

At the beginning, Academician Guo really thought so.

But after reading Gu Lu's article published in Physical Review Letters, Academician Guo became hesitant.

This young man named Gu Lu is really quite talented in physics!

Yes, it is indeed a huge loss to the mathematical community to let such an excellent mathematician as Gu Lu engage in the research of physics projects.

But......

If such a genius with high physical talent is rejected as a pervert, it will be a huge loss to the entire physics community!

After hesitating, Academician Guo finally chose to let Gu Lu join the project team.

Academician Guo did not know what role Gu Lu would play in the next research and development work.

But Academician Guo had a faint feeling.

The emergence of Gu Lu may become a variable in the confrontation between the two countries against quantum computer technology.

…………

Academician Guo's fingers tapped lightly on the tabletop, looking at Gu Lu with a smile.

"Gu Lu, you should know the difficulty of developing a quantum computer, right?"

Gu Lu nodded.

After the end of the report meeting on the 12th, Gu Lu has been preparing for the semiconductor quantum chip project.

During this period, Gu Lu read many books and documents related to quantum computers and semiconductor quantum chips.

At the same time, there is a deeper understanding of the current situation in this field.

Developing a quantum computer is difficult.

What are the requirements for a working quantum computer?

The fidelity of single-qubit logic gates and double-qubit logic gates should reach more than 99%, and the number of qubits should reach more than dozens at the same time, and the operation speed and decoherence time should be within a reasonable range.

This is a summary made by Gu Lu after reading a large amount of literature.

To put it simply, there are four conditions.

The first is qubits, that is, like the bits of classical computers, for classical computers, the more bits they have, the larger the number of operations can be, and the stronger their capabilities, and the same is true for quantum computers.

The second is the quantum logic gate, just like the and, or, and non-equal logic circuits of classical computers, the single qubit logic gate and the double qubit logic gate are the basic units that make up a quantum computer.

The third is fidelity, which needs to reach 99%, that is, only one calculation error can be allowed in 100 operations, and its purpose is to successfully complete quantum computing, and the error rate of each logic gate cannot exceed 1%.

Fourth, the operation speed and decoherence time, the faster the former the better, the longer the latter the better, but often the two cannot be satisfied at the same time.

In order to successfully develop a basic quantum computer, the above five conditions need to be met.

Among these four conditions, the one that best reflects the advantages and disadvantages of a quantum computer is the first, the number of qubits.

The higher the number, the better the performance of the quantum computer.

"Do you know what the highest number of qubits we can achieve at the moment?" Academician Guo looked up at Gu Lu.

"Two bits. Gu Lu opened his mouth and replied.

"That's right, it's two bits. Academician Guo nodded and slowly spoke, "Using the implementation form of semiconductor quantum chips, the maximum number of bits that we can achieve in China is two bits. ”

Moreover, this achievement was achieved by Academician Guo and the people below him.

"But......" Academician Guo let out a long sigh, "According to the news I thought foreign friends brought to me, the United States has used the form of superconducting circuits to realize the research and development of twelve-qubit computers." ”

One is two bits and one is twelve-bit.

Gu Lu now knows why most people are pessimistic when talking about this project.

Because of this gap, it is indeed quite large.

Don't look at the difference in the number of just ten bits, it is difficult to estimate how many technical difficulties are involved.

And once the United States triples that number and achieves research and development work on the number of more than 30 qubits, then maybe the first quantum computer will be available.

"In addition, for two-bit semiconductor quantum chips, we can't guarantee 99% fidelity, and the current average test data is only about 95%. Academician Guo told Gu Lu another piece of bad news.

If you can't reach 99% fidelity, that means it's a failed product.

Computers pay the most attention to the accuracy of calculations, and once the error rate reaches a terrifying figure of 5%, then even if it is developed, no organization wants to use it.

After hearing Academician Guo's words, Gu Lu's mood was a little heavier.

After Academician Guo said this, Gu Lu did feel a heavy pressure.

"So, even so, do you still want to choose to join our project team?" Academician Guo looked at Gu Lu with a smile.

Gu Lu's answer didn't have any hesitation, "I'll join!"