Quantum-Supremacy, which translates to "quantum supremacy".

The concept of quantum supremacy has been around for a long time, and it was later popularized by an American theoretical physicist named John Preskey.

John Preskiel was the first to predict that a computer with more than 50 qubits would be able to surpass all classical digital computers in solving certain problems, and then it could be called the era of quantum supremacy.

However, John Presquill saw the rapid progress of quantum computers today, and he felt that he was a little too full, so he changed the phrase to another level: in the near future, humans will be able to use noisy medium-sized quantum (NISQ) technology.

If John Presquire came to Ye Hua's Science and Technology Villa Manor and saw the quantum computer in the underground library, which had already met DiVincenzo's five standards, it is estimated that he would write an article on error correction when he turned around, and the era of re-exalting "quantum supremacy" had come.

The advent of quantum computers will not turn the world upside down in an instant, but its role in the field of high-tech research and development is immeasurable.

Ye Hua has identified ten application scenarios for quantum computers.

[Digital Quantum Simulation and Analog Quantum Simulation], Ye Hua wants to simulate the human gene array map, and the application of quantum simulation must be involved, which is indispensable.

The other nine application scenarios are quantum optimizer, quantum hardware test platform, quantum annealing, anti-noise quantum loop, quantum deep learning, quantum matrix inversion, quantum recommendation system, quantum semi-definite programming, and quantum acceleration.

Ayako Kitagawa couldn't help but be curious about it: "Quantum computers have been very hot in recent years, it seems that an American scientist said that a quantum computer with 50 to 100 qubits may be able to perform tasks beyond the capabilities of current classical digital computers, I read the news that Google has done 72 qubits, why are you only 64 bits..."

"Clams? Do you mean to look down on you? How dare you ...... I think you owe the day! Ye Hua suddenly looked at her dissatisfied.

"That's right, people have long wanted to eat all day long." Kitagawa Ayako looked at her with a smile, a smile and a charming smile, full of provocative taste.

Seeing her like this, the hook was too straight, Ye Hua didn't take her properly, retracted his gaze and said, "What do those media people know?" You can believe it, Google has achieved 72 qubits, has quantum supremacy arrived? I don't think I've heard Google say that a big prime factor factorization has been done? ”

Kitagawa Ayako retorted, "How did you know? Maybe Google has already done it internally? It's just for business secrecy, just like you. ”

Ye Hua smiled calmly: "Google is a listed company, if there is really such a big breakthrough, it will definitely announce the latest research results as soon as possible to push up the market value." ”

Seeing that Ayako Kitagawa was speechless but pouting, it was very reasonable and strong, Ye Hua wanted to convince her, but it didn't seem necessary to think about it.

She is not a professional in this area, and the science of quantum mechanics itself is mysterious, and she can talk to an insider for three days and three nights in any quantum sub-discipline, let alone a layman?

After Ye Hua confirmed that all the data and equipment were working properly, he swept off all the holographic floating screens in front of him with his big hand, turned to her and said, "You go and bring me the emergency medical kit." ”

Kitagawa Ayako didn't know what he was going to do with the medical first aid kit, but she walked out of the basement to get it.

Looking at the direction in which she disappeared, Ye Hua withdrew his gaze and continued to work.

For women, they may not be convinced, but they can take it daily.

As the so-called rivers go down, protracted, like the sun rising.

Speaking of Google's news of 72 qubits, this is largely the result of half-understood media or hype, or misleading, which can only deceive the people who don't know the truth, Presquier said 50~100 qubits refer to qubits that can perform parallel operations at the same time, that is, quantum logic bits.

This involves a "quantum coding" problem, because all calculations with qubits are probabilistic, and there is an error, so more qubits need to be sacrificed to correct the error.

The so-called "quantum coding" is therefore also called "quantum error correction code", and Google's so-called 72 qubits are only at the physical level, and each qubit can be placed there more, but if you can't perform logical operations, it is useless to put more.

At the logical bit level, the 72 Qubits that Google is engaged in are equivalent to 9 logical bits, because every 8 need to be corrected as a group, and each group actually has only 1 logical bit.

Even this is not 100% accurate, because the use of "quantum error-correcting codes" means that Google's quantum computer does not solve the fourth principle of the DiVincenzo criterion, which is to have a solution to effective decoherence.

The quantum computer that Ye Hua is now building has met the five standards of DiVincenzo, and it is a quantum computer in the true sense, these 64 bits refer to the qubits that can perform parallel operations at the same time, corresponding to Google's 9 qubits, and Google's corresponding 72 Qubits, and Ye Hua's quantum computer is 128 Qubit.

IMB also has a large number of Qubits, but the actual logical Qubits are only about 6.

Google uses every 8 groups to correct errors, and the accuracy is about 70~80%, which is the fidelity of the logic gate, he has to do this, in fact, the more error correction groups, the closer to the correct answer, but it can never be guaranteed to be 100% accurate, this is a hard injury, the current quantum computer research institutions around the world, except for Ye Hua to solve the hard problem of decoherence, no one can solve it.

As for what the quantum computer developed by Ye Hua uses to make qubits, of course, it uses a quantum dual-state system, that is, two degrees of freedom of a photon to make two qubits.

64 qubits are 64 photons, or 128 qubits, and they are entangled with each other, called GHZ states, which is a special kind of quantum entanglement.

It is actually a very difficult time to use multi-quantum GHZ states, and the 64 photons used by Ye Hua used the momentum of these photons and the orbital angular momentum to complete the preparation and characterization of 128 Qubit GHZ states.

In fact, many physicists in Europe and the United States believe that the road of using linear optics to make quantum computers is not going to work, that is, directly using the polarization, angular momentum, and orbital angular momentum of photons to make qubits.

However, Prof. Pan Jianwei's team took the lead in realizing the preparation and characterization of GHZ states with three degrees of freedom: polarization, momentum and orbital angular momentum of photons.

Ye Hua directly completed the preparation and characterization of the GHZ state with two degrees of freedom.

As for why it is difficult, it is so difficult that it cannot be done, because it is too difficult to integrate, and it takes a lot of equipment to ensure the coherence and lifetime of photons.

In fact, it is.

In the basement of the villa, the quantum computer developed by Ye Hua is extremely large, and a lot of equipment and resources are consumed, just to ensure the coherence and longevity of optical quanta.

Photons are very fragile, and a single photon can be absorbed anywhere it touches, so it is almost impossible to make thousands of qubits and achieve integrated miniaturization with existing technologies and materials.

If it can't be integrated, it means that it can't be popularized.

Ye Hua actually has a way to protect the coherence and longevity of photons, that is, to solve it through "fields", but he doesn't do it now, which will consume more of his time and energy to make breakthroughs in new technologies, the preparation of new materials, and so on.

He has not forgotten what he did in the first place, just to simulate his own genetic array and obtain a complete genetic map to implement controllable mutations.

Now that there is a quantum computer that can be used, that's it, and we'll talk about that later.

Europeans and Americans think it can't be done, but Professor Pan Jianwei has found another way, it is difficult to integrate more photons, but you can use multiple degrees of freedom of a photon to make qubits, this is the power of Professor Pan Jianwei.

This is not what Ye Hua wants to make up the most, he just goes one step further.

This method is indeed feasible, but the cost is a little higher, but for Ye Hua, as long as 50~100 can be calculated, it is enough to build a quantum computer.

……