2. The Question and the Responses from DeepSeek
The question and the answer from DeepSeek demonstrate the wrong concepts hold by material scientists, that is material, film, and interface have been confused.
“Under what circumstances is microwave absorption only related to the interface of the material and not to the properties of the material itself?”
It was a good question since it represents the wrong concepts believed by material scientists and a discussion about the responses offered by DeepSeek helped us to identify why many of the related papers do not mention the opposite theory at all. It also shows that only commonly accepted answers can be expected from AI and that innovative discoveries are difficult to be offered from machine intelligence at its current stage of development.
The correct answer to the question is that when there are front and back interfaces assembled to form a device like film, the absorption mechanism of the device will be changed to wave superposition instead of the attenuation power of the material. It should be noted that the film does not absorb microwaves if the material does not absorb even though the absorption mechanisms of the film and the material are different. However, as expected, the responses from DeepSeek were based on the wrong concepts from current theories confusing film and material, interfaces between material particles and those of the film, and interface of film and in its isolated state.
Two versions of the response have been provided from DeepSeek and one is presented below while the other version is provided in the
Supplementary Materials B.
“Well, what the user is asking is under what circumstances the absorption of microwaves is only related to the interface of the material, and not to the characteristics of the material itself. This question seems a bit challenging because microwave absorption is often closely related to the electromagnetic parameters of materials such as dielectric constant, magnetic permeability, etc. But users may want to know if there are special circumstances that make interface effects the dominant factor, while the properties of the material itself become less important.
Firstly, I need to recall the fundamental principles of the interaction between microwaves and materials. The absorption of microwaves mainly involves mechanisms such as dielectric loss, magnetic loss, and conductive loss, all of which are related to the inherent properties of materials. But users want to know if there is a situation where interface effects dominate, which may involve reflection, transmission, and interference phenomena. In this case, the design of the interface structure may be more important than the properties of the material itself.
For example, when the material is very thin, such as metamaterials or metasurfaces, the thickness of the material is much smaller than the wavelength of microwaves. Electromagnetic waves mainly interact with interface structures, such as periodic structures or subwavelength structures. The design of these structures can change the reflection and transmission characteristics of electromagnetic waves, while the dielectric constant or magnetic permeability of the material itself may have a smaller impact. In this case, interface effects may become the dominant factor.
In addition, it is also possible to enhance the absorption effect by designing impedance matching different layers in a multi-layer structure, so that the incident wave undergoes multiple reflections and interferences at the interface. At this point, although the material properties of each layer are important, through structural design, the overall absorption effect may depend more on the interactions between interfaces rather than the properties of a single material itself.
Another scenario is surface plasmon resonance, where electromagnetic waves interact with free electrons on the metal surface, exciting surface plasmon polaritons at the interface. In this case, absorption may be closely related to the interface structure, while the internal properties of the material have a relatively small impact.
However, it is necessary to verify whether these situations truly render the properties of the material itself irrelevant. For example, in metasurface design, although structure is crucial, the choice of material (such as metal or dielectrics) still affects the performance of the structure, so it may not be completely unrelated. But the user's question may be whether there are certain extreme situations, such as when the material thickness approaches zero, or when the structural design completely compensates for the material's own characteristics, where interface effects dominate.
It may be necessary to consult some literature or theories to see if such theoretical models exist. For example, in an ideal situation, if the thickness of the material approaches zero, but the interface structure is designed very cleverly, absorption may be mainly determined by the interface structure. Or at certain frequencies, structural design can make the internal losses of the material negligible, while multiple reflections and interferences at the interface lead to absorption.
The concept of impedance matching also needs to be considered. When the impedance of the material is perfectly matched with free space, microwaves will completely enter the material without reflection, and absorption may be determined by internal losses of the material. But if impedance matching is achieved through interface structure and the loss of the material itself is low, then absorption may depend more on the design of the interface structure rather than the loss characteristics of the material itself.
For example, using a multi-layer structure, the thickness and material parameters of each layer are designed to cause destructive interference of the incident wave at the interface of each layer, thereby reducing reflection and increasing absorption. In this case, although material parameters are still important, the overall absorption effect may depend more on structural design, namely the interaction between interfaces, rather than the intrinsic properties of a single material.
In addition, under certain resonance conditions, such as Fabry-Pérot Resonance, electromagnetic waves may form standing waves after multiple reflections inside the material, resulting in strong absorption at specific frequencies. In this case, the position and intensity of the absorption peak may be determined by the thickness of the material and interface reflection, while the loss parameters of the material itself may affect the absorption bandwidth, but the resonance conditions themselves are determined by interface and structural parameters
In summary, possible scenarios include:
1. Ultra-thin materials or metasurface designs are dominated by structural effects.
2. Multilayer interference structure, interface reflection, and phase matching determine absorption.
3. Surface plasmon resonance and interface excitation dominante absorption.
4. Fabry-Pérot resonant cavity, thickness and interface reflection determine the resonance conditions.
Further verification is needed to determine whether these situations truly render the properties of the material itself irrelevant, or whether the coordination of material parameters is still necessary. For example, in metasurface design, although structure is crucial, the choice of material (such as metal or dielectric) still affects performance. However, in some extreme cases, structural design may compensate for changes in material properties, making the absorption effect mainly determined by the interface structure.
In addition, it may be necessary to consider the limit cases in the theoretical model, such as whether absorption may only be caused by interference from interface reflection when material loss approaches zero. For example, in an ideal lossless medium, by designing a multi-layer structure to cancel out reflected waves and restrict transmitted waves, complete absorption can be achieved at a specific frequency. In this case, the absorption mechanism may be independent of the material's own losses and determined only by interface interference.
For example, in Coherent Perfect Absorption, the energy is completely absorbed by the interference of two coherent waves. In this case, the conditions for absorption may only depend on the reflection and transmission characteristics of the interface, but not on the loss parameters of the material. However, this may be a special case and requires specific experimental conditions.
In summary, the possible answer is: when the absorption of microwaves is mainly determined by the reflection, transmission and interference effects at the interface, and the loss inside the material can be neglected, for example, in the case of ultra-thin structure, multi-layer interference design or coherent perfect absorption, microwave absorption may be mainly related to the interface, and has nothing to do with the electromagnetic properties of the material itself (such as dielectric constant, magnetic permeability). In this case, structural design becomes the dominant factor, not the material's intrinsic properties. “
We have checked this question from ChatGPT and DeepSeek with the same question and obtained similar responses. The responses we obtained from DeepSeek also include the additional point that material property can be neglected for the perfect impedance matching for the wrong reason that for perfect impedance matching, the incident microwaves did not penetrate the film, and all waves were absorbed by the front interface.
3. Comments on the Response from DeepSeek
Reflection loss
RL/dB for metal-backed film is always used wrongly in publications to characterize the absorption from material.
RL is a parameter for film rather than material [
19] and thus it can only be used to characterize film and not material.
A block of material behaves as a film since it has two parallel interfaces [
9] and thus
RL can be used to characterize a block of material even though it cannot be used to characterize material in general. Therefore, a block of material can have properties not possessed by a material. Only parameters such as the relative permittivity
εr and the permeability
μr can be used to characterize material [
4]. It should be known that microwave absorption of a material is characterized solely by
εr and
μr values of the material even though there are other parameters of derivatives of
εr and
μr such as attenuation power constant
αP and the dielectric and the magnetic loss tangents have the same function.
The interfaces between material particles have often been used to explain the absorption characterized by
RL/dB and have a dominant effect on material absorption [
20,
21]. Indeed, there is a clear relationship between
RL and the values of
εr and
μr which are determined by material structure, but there is no clear relationship between
RL and material structure or the interface structure of the material. Thus, the research on the relationship between
RL and material structure is not scientifically accurate. The scientific design of a research program should first determine what values of
εr and
μr are required to achieve the desired value of
RL, and which material structure might have these values [
22]. However, key research on the relationship between material structure and the values of
εr and
μr has seldom been done. It should be noted that uniform material with interfaces between material particles is still a single phased material with averaged values of
εr and
μr [
1] and the same is true for multi-layered film [
10]. The effects of material structure such as split-ring resonators and the Maxwell–Wagner interfacial polarization effect can change the values of
εr and
μr and thus affect the absorption of the film. The sensible research should investigate the relationship between absorption and split-ring resonators or of the Maxwell–Wagner effect rather than the relationship between the value of
RL and those effects since other device parameters such as film thickness also contribute to the value of
RL. These conclusions demonstrate that discussing the relationship of absorption represented by
RL/dB and interfaces between material particles make little sense particularly as, experimental results can without exception, be shown to conform to the newly established wave mechanics theory taking into account the values of the material properties of
εr and
μr.
The functions of the two parallel interfaces for film are quite different from those of between material particles for microwave absorption. The interfaces of the film offer wave superposition [
2,
5,
8,
23,
24,
25], while the interfaces between material particles only provide the average values of
εr and
μr [
1]. It should be noted that the interface does not absorb microwaves [
7]. The effects of the interfaces between materials on absorption do not arise because an interface absorbs microwaves but because the values of
εr and
μr are affected by material structure. Thus, interface only changes the average values of
εr and
μr rather than absorbing microwaves by itself. Material attenuation is of monotonic function [
5,
24] while
RL/dB has a wave shape since there are angular effects on
RL/dB for film [
2]. Film behaves as material only when the front interface disappears under the condition
ZM =
Z0 where all incident microwaves enter the film.
Thin film has apparent angular effects on absorption [
2,
22] and thick film behaves more like material with monotonic attenuation power [
22]. However, thin material, metasurfaces, and subwavelength structures were used in these responses related to interfaces within material other than the concepts of thin and thick films. The concepts of thin and thick film were developed to differentiate film and material [
22]. The concept of the interface structure of material often neglects the fact that an interface does not absorb microwaves [
7] and the reflection coefficient of an interface is often wrongly used to evaluate absorption from film [
6,
26,
27,
28].
The absorptions of material and film have not been differentiated in DeepSeek’s responses representing the common mistake of confusing film with material in current mainstream microwave absorption research. The responses represent the common practice of using interface structure within materials to account for the absorption peaks represented by
RL/dB. Such practice has never achieved any valuable conclusions since it has also wrongly attributed the effect of film thickness on
RL to the effect of interface structure. The responses also reflect the fact that the interfaces of film and the interfaces within material have been confused in current theories. The interfaces within the material change the average values of
εr and
μr. The interfaces of inner layers within a multi-layered film function the same as the interfaces within the material [
10] and using multi-layered film does not diminish the effects of
εr and
μr on absorption. On the other hand, the two parallel interfaces of the film are only responsible for wave superposition rather than changing the values of
εr and
μr.
The confusion between film and material has led to the establishment of the wrong impedance matching theory which was also involved in the responses. Impedance matching theory is used to explain the absorption peak of film when the input impedance of the film
Zin is not equal to the characteristic impedance of free space
Z0. However, at perfect impedance matching where all the incident microwaves enter the film, the front interface of the film disappears and there is no absorption peak at all since the film behaves as a material under these circumstances [
5,
22,
24,
29,
30]. It should be noted that the impedance matching theory in microwave absorption is not the same as the correct and rigorous impedance matching theory in circuit theory.
It is true that among the set absorption peaks for a film the peak with |
Zin| the closest to |
Z0| is the strongest but the reason in not that the greatest penetration of microwaves occurs then. The real reason is that the two reflection beams from the two parallel interfaces at front and end of the film complete cancel each other when |
Zin| = |
Z0| when the phase difference of the two beams is π. [
2,
8]
It should be noted that Fabry-Pérot Resonance relates to film rather than material occurs due to complete wave cancellation rather than real resonation. Almost all the absorption reported in microwave absorption papers are from damped oscillations rather than from the resonance absorption.
The response from DeepSeek that “in an ideal lossless medium, by designing a multi-layer structure to cancel out reflected waves and restrict transmitted waves, complete absorption can be achieved at a specific frequency” represents a common mistake in current theory concerning interface structure of material and absorption. When a specific material does not absorb microwaves, the film cannot absorb microwaves even if the relevant beams are out of phase by π [
2,
24,
31]. The principle that a film composed of lossless material does not absorb microwaves is ensured by energy conservation [
7].
Without correct theoretical guidance, experimental data were used to support the wrong theory. A theory that has been repeatedly verified by experiment can still be a false theory. Until the geocentric theory was disproved by the heliocentric theory, all experimental observations were used to support the false geocentric theory; Until the phlogiston theory was finally disproved by mathematical logic, all previous experimental results had been used to support the phlogiston theory; Until the new wave mechanics theory of microwave absorption is established, all experimental data have been reported as being consistent with the erroneous prevailing theory of microwave absorption.
In the past decades experimental data has been used to support the current wrong theories of microwave absorption because the correct theory was not available. As a consequence, when the correct new wave mechanics theory of microwave absorption was developed it was not taken seriously, with the result that mainstream scientists still adhere to the current erroneous mainstream theories.
It was revealed that inconsistencies in established theories cannot easily be identified without theoretical understanding because of the ingrained mis-conceptions. [
18] AI can be very successful when based on correct theories, but not when it has been trained on commonly accepted but wrong theories. Currently AI modes are trained on current theories, and currently it cannot be expected to recognize inconsistencies in current theories, though hopefully this may change in the future
Here the responses of DeepSeek from a question are analyzed to clear up the concepts hindering material scientists in appreciating the newly established wave mechanics theory for microwave absorption. Since there are few comments on the new mechanics theory, the responses from DeepSeek represent the current thinking of mainstream scientists. It reveals that the mis-conceptions such as using reflection coefficient of interface to characterize microwave absorption, the film with lossless material absorbing microwaves by wave cancellation, are responsible for the fact that material scientists are reluctant to give up the theories that have been proved wrong. Neglecting the fact that the effects of film thickness on absorption have also been mistakenly described as being caused by the effects of interface structure of material on absorption has made the research community insist on the false relationship between interface structure of material and the peak values of RL/dB. This shows that AI can be helpful in identifying what mis-conceptions have prevented the acceptance of the correct wave mechanics theory.
Wrong theories cannot become correct just because they have survived for a long time and have been supported by a majority of scientists. [
32,
33,
34,
35] The wrong concepts not only have led to wrong theories; they also have made it difficult to recognize the inadequacies of the theories.
The current situation in science has been well summarized in three comments, first, “Yes, error detectors can make research less comfortable — but that discomfort is healthy … journals need to make clearer and firmer commitments to self-correction” [
36]: second, “Scientists are often tardy in fixing basic flaws in their sciences despite the presence of better alternatives” [
37] and third, “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it”. [
38] That scientists are reluctant to accept new ideas is an unsolved problem that has repeatedly occurred in history and thus is important to be addressed through concrete examples. It is relevant to conclude with Nobel laureate Ding Zhaozhong’s words: "Every one of my experiments has been opposed by many people, especially the experiments on the space station … First-rate scientists can look forward and make judgments about the future … Opposition is not a bad phenomenon, but it is meaningless to solve scientific problems by voting. The progress of science is that the majority obeys the minority. Only when a very small number of people overthrow the views of the majority can science move forward." [
39]