After being replaced with micro-nano structural materials, the collection efficiency has been greatly improved compared to before, but it has only been maintained at around 12%.

Moreover, the collection efficiency fluctuates significantly, is very unstable, and the quality of the light source has also declined.

Such experimental results have very little practical significance.

As for this new experiment, everyone hopes to achieve higher collection efficiency and ensure the quality of the light source.

After the preparations are ready, the experiment is about to begin.

"We first use a picosecond laser with a repetition frequency of 79 MHz to perform two-photon resonance excitation." Wang Xiangwu said.

Wu Hong used the instrument to adjust the laser parameters to ensure the wavelength of the laser between the exciton line and the double exciton line.

At the π pulse, an avalanche photodiode is used to count the photons.

As the experiment progressed, the real-time absorption efficiency values ​​were also reflected in the instrument.

When everyone saw the data, they all looked excited.

"Is it so high? The collection efficiency has actually reached about 90%!"

Compared with the 12% last time, such an increase is undoubtedly a qualitative change.

Of course, the current collection efficiency is only rough and has not been modified.

The actual collection efficiency should be lower.

After completing several sets of data, Wang Xiangwu decided to further analyze these sets of data first.

After all, the 90% collection efficiency just now still has a certain amount of moisture.

Only through the corrected collection efficiency can it be more convincing.

Wu Hong opened the software, completed the synchronization of the data, and processed the previous sets of data.

In the actual data processing process, the loss of the optical path needs to be deducted and APD efficiency correction is carried out to obtain the final and more accurate collection efficiency.

After completing the data processing, the final collection efficiency appears.

"85.3%? It's already very good!"

Although it has not reached such ultra-high efficiency yet.

But compared with the previous 12%, this is undoubtedly a huge improvement.

"Although this is just the collection efficiency of a single photon, it has indeed far exceeded our expectations. Such a high collection efficiency can be said to be practical!"

Seeing the final result, Wang Xiangwu was very excited.

This proves that the new light source structure designed by Xu You is indeed very successful!

Wu Hong was also very excited about this.

Although Wu Hong had a premonition when he saw Xu You's design drawings, this would definitely be a breakthrough design.

But after all, theory and practice are not completely equated. Only by truly making ideal experimental results can the theory be proved to be correct.

Over the past few months, Wu Hong has been waiting for the day when the experiment begins.

Today's experimental results finally prove that this new light source structure is successful.

"Next, let's start an experiment on entangled photon pairs."

Compared with single photons, the collection efficiency of entangled photon pairs is lower.

But as long as it can reach more than 50%, it will be relatively good efficiency.

After completing several sets of experiments, Wu Hong once again corrected the efficiency value.

Unlike single photons, this time, the preparation efficiency and purity of the bisexonic state need to be corrected.

When everyone saw the corrected collection efficiency, they were once again excited.

"75.4%! It's already much more than 50%!"

It is already a very shocking data to be able to collect the entangled photon pairs at such a level.

All of a sudden, the researchers in the entire laboratory were able to release their depressed mood for several months.

This project about the new generation of quantum computers in China is of great significance in everyone's mind.

Even if we cannot publish scientific research results to the public in the short term, we will not ignore this project.

As top scientific researchers in China, they all want to make their own contribution to the development of national cutting-edge technology.

"Okay, all are calm, the experiment is not over yet. We still have a lot of work to do next."

Wang Xiangwu tried hard to suppress his inner joy, urged everyone to calm down and continue the next experiment.

High collection efficiency alone cannot fully represent the practicality of the light source structure.

In addition, it is also necessary to measure the entanglement fidelity and indistinguishability of photons.

After a few days of experiments, all data were also measured and corrected.

In addition to very high collection efficiency.

The entanglement fidelity of photons and the indistinguishability of photons are also within a very high range.

"By grating spectroscopy, the exciton photon and the two exciton photon were sent to one end respectively, and we finally obtained an entanglement fidelity of 88.6%. Through the interference measurement of the two exciton photons, the exciton and the two exciton photons are

The indistinguishability also reached 90.1% and 90.3% respectively.”

The experimental team no longer had any extravagance for such results.

No matter from any perspective, the new light source structure designed by Xu You can be said to be very successful.

Such breakthrough achievements are not only able to publish papers in the top journals, but also can be directly used in breakthrough technologies on optical quantum computers.

This time, Xu You became the key to the project and contributed the most important light source structure design.

Even though the other members of the experimental team did not have the outstanding contributions as Xu You, they also made their own efforts for this topic.

After a brief celebration, Wang Xiangwu quickly decided to inform Academician Han Shubin of this result.

"Because it is an internal project, you don't need to pay too much attention to formatting, just express the key theories, images, and experimental data. When the project paper is officially submitted, it will not be too late for us to provide standard papers."

Wang Xiangwu knew that on the other side of the distant ocean, the United States must be conducting the research and development of a new generation of quantum computers.

At this critical moment, every breakthrough in new technology is very important.

After all, if you are not submitting papers to journals, you don’t need to pay attention to formatting.

After learning the news, Han Shubin immediately invited Wang Xiangwu's experimental team to the Chinese Academy of Sciences.

After all, some things cannot be fully reflected through papers alone, and more detailed communication is required.

On the agreed day, Wang Xiangwu brought the core members of this project to the Chinese Academy of Sciences together.

As the designer of the new light source structure, Xu You is naturally among them.

In the office, Han Shubin was drinking tea while waiting for the arrival of Wang Xiangwu's experimental team.

"Ji University's scientific research team has performed well recently. Last time, Qiaosen's experimental group made good experimental results in the field of superconducting quantum. This time, Wang Xiangwu's experimental group made a breakthrough in the field of photoquantum."
Chapter completed!