Conducting Verification of Quantum Superabsorption

Chapter 111 Conducting Verification of Quantum Superabsorption

Traditional chemical batteries rely on redox reactions to store and release chemical energy through the breaking and recombination of chemical bonds.

Common lithium batteries and lead-acid batteries belong to this type of energy storage mechanism.

Within this framework, the larger the battery volume, the more substances participate in the reaction, the greater the internal resistance, and the slower the charging speed. This is a physical law that no chemical battery can break.

However, the energy storage form of quantum batteries does not belong to traditional chemical energy. It directly relies on the energy level transitions and quantum coherence effects of quantum systems to store energy, and completes the transfer and retention of energy in the form of photons and quantum states.

The entire process does not rely on chemical reactions, nor does it involve energy changes in chemical bonds, which is completely different from the energy storage logic of traditional chemical energy.

The core mechanism described in the document is that when multiple molecules are placed in an optical microcavity, they generate a collective synergistic effect through quantum entanglement.

In simple terms, with each additional molecular unit involved in the synergistic process, the absorption efficiency of the entire system for photons increases superlinearly, rather than decreasing with increasing volume as is the case in traditional chemical systems.

This is similar to a choir. The voice of an individual singer is limited, but when a well-trained choir sings together, the sound pressure level far exceeds the sum of the voices of all the singers individually.

This "1+1 is much greater than 2" effect has a specific name in quantum mechanics: superradiation.

Quantum batteries utilize the reverse process of this superradiation effect, namely, superabsorption.

At this moment, Lin Chuan glanced at Luo Xiangdong and said, "For the next few months, what you need to do is to experimentally verify this superabsorption effect. You don't need to build a complete battery; just observing the superlinear charging rate and storage capacity characteristics will be a partial victory."

Luo Xiangdong nodded: "OK."

In the days that followed, with the necessary funding and manpower in place, Luo Xiangdong led the quantum energy storage project team to begin theoretical verification.

Lu Jing was responsible for building the femtosecond laser experimental platform, which is an extremely complex ultrafast optical system. The core of the system is a Ti:sapphire femtosecond laser with a pulse width of less than 100 femtoseconds.

The pulses emitted by femtosecond lasers are extremely short, and in terms of time resolution, they are equivalent to a high-speed camera capable of observing molecular motion, making them an essential tool for observing the charging dynamics of quantum batteries.

This laser is extremely sensitive to environmental vibrations and temperature; even the slightest vibration can cause the optical path to deviate.

However, the setup process went quite smoothly. Lu Jing placed the entire system on an active vibration isolation platform, and the temperature in the laboratory was controlled with an accuracy of ±0.1 degrees.

He and a few young engineers spent two weeks calibrating the optical path, during which three frequency doubling crystals were burned out because the light spot deviated from the optimal path.

Chen Zhiyi was responsible for preparing the microcavity samples. The core energy storage medium of the quantum battery is an organic dye molecule called Lumogen-F. This molecule has an extremely high fluorescence quantum yield and can efficiently absorb photons and enter an excited state.

Her task was to encapsulate dye molecules of different concentrations into optical microcavities.

An optical microcavity consists of two highly reflective mirrors sandwiching an extremely thin active layer, only a few hundred nanometers thick, equivalent to one-thousandth the thickness of a human hair.

The size of this cavity determines the modes in which photons can exist, directly affecting the strength of quantum coupling between molecules.

Based on the theoretical model provided by Lin Chuan, Chen Zhiyi and his team spent more than ten days exploring and finally found suitable spin coating parameters.

The initial batches of samples either had uneven film thickness or failed to meet the specular reflectivity requirements. After repeated adjustments to the spin coating speed, solution concentration, and annealing temperature, the fourth batch yielded microcavity samples that met the design requirements.

Luo Xiangdong was responsible for coordinating the entire experimental process and handling theoretical calculations.

The mathematical model in the technical data provided by Lin Chuan was rebuilt, and the expected absorption curves for different numbers of molecules were generated, providing a benchmark for subsequent experimental data.

As the head of DeepBlue Technology, Lin Chuan didn't stay in the project team every day, but he would still come over to check on the progress from time to time.

By late April, all preparations were complete.

The femtosecond laser platform has been debugged, the microcavity sample has been prepared and shipped, and the test plan has passed Lin Chuan's review.

After entering May, the first verification experiment was carried out.

However, the experimental results showed that nothing was observed; to be precise, some signals were observed.

However, the signal-to-noise ratio is too low to correspond to the characteristic curve predicted by theory, and the data looks like pure noise.

Lu Jing inspected the optical system and found no faults.

A new batch of samples was replaced and retested, but the results still did not improve.

The project team repeatedly checked the experimental parameters, and theoretically, the pump power and wavelength range that should be able to induce the superabsorption effect were all correct.

The experiment failed three times in a row.

However, good news soon arrived: the cause was found. When Lu Jing checked the optical path, he discovered a systematic time deviation of about 30 femtoseconds between the time it took for the pump light to reach the sample and the time it took for the probe light to reach the sample.

This delay is extremely small and can be completely ignored in routine experiments.

However, in experiments requiring femtosecond-level time resolution, the deviation is sufficient to cause the pump-probe timing to be completely out of sync.

The team adjusted the delay lines and recalibrated the optical path.

On May 16, the fourth experiment began.

This time, the probe light clearly captured a characteristic signal the instant the pump laser pulse irradiated the microcavity sample.

The absorption efficiency exhibits a superlinear growth curve that perfectly matches theoretical predictions as the pump energy increases.

More importantly, when the team switched to a large-size microcavity sample with more dye molecules, the charging rate per unit volume not only did not decrease, but actually increased significantly.

This perfectly verifies the core prediction of the quantum superabsorption effect.

In the lab, Luo Xiangdong pushed his goggles up to his forehead and looked at the curve on the screen, exclaiming, "The boss is a genius!"

In the afternoon, Luo Xiangdong compiled a phased verification report for the project team.

The report's core conclusion is that the experiment successfully observed ultra-wide-ranging charging rates and storage capacity characteristics, which are in complete agreement with theoretical predictions. This marks the first time that a quantum battery prototype has been verified in an organic microcavity system.

The report was delivered to Lin Chuan's desk that afternoon.

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At this moment, besides Lin Chuan, Shen Yuxin was also in the office.

Lin Chuan was reviewing Luo Xiangdong's report. He then signed his name on the last page and added a note below:

[Proceed to the next stage. Objective: To complete the full closed loop of energy storage and output, and to produce the first demonstrable quantum battery prototype.]

A moment later, Lin Chuan handed the materials to Shen Yuxin: "Give this to Luo Xiangdong."

Shen Yuxin nodded: "Okay."

As Shen Yuxin left the office, Lin Chuan marked a time point in his mind.

If all goes well, the second phase should be completed in the second half of the year, and the first industrial prototype of the quantum battery could be available by next year.

By then, many things will need to be accelerated.

We definitely need to submit a report to the military about this matter, and then see what the country's plans are.

Such advanced technology must be promoted for both military and civilian applications.

However, the specifics of how to proceed and the pace of implementation must be discussed with the government beforehand. DeepBlue Technology absolutely cannot announce its plans to the public without prior notice.

In late May, the Z-7 experimental building entered a new phase.

The successful proof-of-principle demonstration greatly boosted the morale of the entire quantum energy storage project team.

But everyone knows that the real show is just beginning. The superabsorption effect observed earlier essentially only proved that the physical phenomenon of "light energy being captured and temporarily stored" is real.

However, there are still several technical challenges between us and a truly functional quantum battery prototype.

The biggest problem is that energy cannot be stored.

In previous experiments, organic dye molecules entered a quantum coherent state under the excitation of femtosecond laser pulses, and their energy was "frozen" in the molecular array in the form of excited state.

However, this frozen state is extremely fragile. Random thermal motion between molecules, defect scattering inside the microcavity, and even weak electromagnetic interference from the external environment can all lead to rapid decoherence of the quantum coherent state.

In layman's terms, it means that energy is lost in a very short time, in the form of heat or other forms.

During the proof-of-concept phase, the team only measured the spectral signal during the charging process and did not attempt to extract the energy.

The measurement itself is completed at the femtosecond level, so the problem of decoherence is not exposed.

However, to make a truly usable battery, the energy storage time must be increased from the femtosecond level to the second level, or even the minute level.

This means that reducing the decoherence rate to less than one billionth of the current level is as difficult as requiring a pot of water to remain boiling for an entire day without heating or heat preservation.

In June, Lin Chuan held a technical discussion meeting with several key members of the project team.

At this moment, Luo Xiangdong, Lu Jing, and Chen Zhiyi were also in Lin Chuan's office.

A whiteboard in the office was covered with formulas and process flowcharts, with several outlines of solutions marked with crosses next to it.

Luo Xiangdong spoke first: "There is only one core bottleneck at present: the decoherence is happening too quickly."

He picked up a laser pointer and pointed to a set of data on the whiteboard, adding, "The best quantum coherent state lifetime we measured in the microcavity was only 17 femtoseconds."

What does this mean? Light can only travel 5 micrometers in 17 femtoseconds.

Luo Xiangdong continued, "In such a short time, the energy was dissipated in the form of thermal radiation before it could be extracted."

At this moment, Lu Jing stood up and walked to the whiteboard. He picked up a marker and drew a simplified energy level diagram in the blank space.

"I analyzed two root causes of decoherence."

"The first is spontaneous radiation coupling between molecules. When a large number of dye molecules are in an excited state at the same time, their dipole interactions will generate a cascade of de-excitation channels."

"Simply put, when one molecule falls back to its ground state, it causes surrounding molecules to fall as well, like dominoes."

At this point, Lu Jing drew an upward arrow next to the energy level diagram and labeled it "pump," then drew a series of downward arrows next to it and labeled it "cascade de-excitation."

"The second issue is mode leakage within the microcavity itself. An ideal optical microcavity should be a perfect Fabry-Perot cavity, where photons reflect back and forth and can theoretically be trapped inside indefinitely."

"However, actual microcavities cannot be perfect. The reflectivity of a mirror cannot be 100%, the refractive index of the medium has microscopic fluctuations, and there are nanometer-level parallelism deviations between the two reflecting surfaces of the cavity. These small defects combined form a 'light leakage' channel."

Lin Chuan nodded after listening, his expression not changing much, which was within his expectations.

After a moment, Lin Chuan asked, "Have you found a solution?"

Lu Jing shook his head: "Not for now."

After thinking for a while, Lin Chuan drew a simple set of molecular structure sketches on the whiteboard.

"Changing the energy storage medium is one solution, and Lumogen-F is an off-the-shelf commercial dye molecule, but it is not designed for quantum batteries. Its excited-state lifetime is inherently short, and the way the molecules are packed together can lead to severe concentration quenching."

At this point, Lin Chuan looked at Lu Jing: "I'm trying to customize and synthesize a batch of new organic molecules. The core idea is to introduce steric hindrance groups into the molecular structure to separate adjacent molecules and reduce dipole interactions."

Lu Jing's eyes lit up immediately, and he nodded: "That makes sense, I understand."

A moment later, Lin Chuan turned to look at Chen Zhiyi, whose main job was to oversee process integration. Lin Chuan looked at her and said, "There's also the optimization of the microcavity design. The current microcavities use distributed Bragg mirrors, which consist of alternating layers of high and low refractive index media."

"In theory, increasing the number of layers can improve reflectivity, but stress accumulation during the manufacturing process can lead to film cracking."

Lin Chuan paused, then added, "Let's try a medium-metal composite reflector solution, replacing the top mirror with an ultra-thin silver film plus a medium protective layer, which will reduce the manufacturing difficulty while maintaining high reflectivity."

Lin Chuan handed a document to Lu Jing: "I've already designed the synthesis route, which consists of seven reaction steps. If we were to hire an external CRO company, the process would take about two months, but we have our own organic synthesis lab."

Lu Jing took the document, glanced at it, and then said, "I can lead a team to do it myself. We should be able to produce the first batch of samples within three weeks."

Then, Lin Chuan looked at Chen Zhiyi: "Approximately how long will it take you to verify the new microcavity solution?"

Chen Zhiyi replied, "The optimization of process parameters will take about two weeks, plus testing, for a total of three weeks, which can be done in parallel with Lu Jing's work."

Lin Chuan nodded, and after a moment's thought, he turned to Luo Xiangdong: "Draw up the timetable. I need to see the test data for the first batch of new molecules and new microcavities in three weeks."

Luo Xiangdong quickly jotted down a few notes in his notebook: "No problem. There's one more thing: the design of the discharge circuit needs to be started in advance."

He added, "Previous experiments only measured the signal in the optical domain, without performing electrical extraction. Once Lu Jing and his team have solved the energy storage time problem, the next step is to extract the energy of the excited state in the form of electrical energy. The design of the discharge circuit, impedance matching, and power management all require time."

Lin Chuan thought for a moment and said, "Then let's transfer two more power electronics engineers from the Aurora project team, have them sign confidentiality agreements, and report to the quantum energy storage project team as soon as possible."

Luo Xiangdong nodded: "Okay, I'm all set."

Lin Chuan looked around at everyone: "Does anyone have anything to add? Okay, if not, then the meeting is adjourned."