Near-field thermal radiation regulator based on semimetal and radiation heat flow regulation method thereof

Abstract

The invention relates to the technical field of near-field heat radiation, and provides a semi-metal-based near-field heat radiation regulator and a radiation heat flow regulation method thereof. Wherein the emitter sequentially comprises a first semi-metal layer, a first dielectric layer and a second semi-metal layer; the receiving body sequentially comprises a third semi-metal layer, a second dielectric layer and a fourth semi-metal layer; the second semi-metal layer and the third semi-metal layer are oppositely arranged, and an adjustable distance exists between the second semi-metal layer and the third semi-metal layer; according to the near-field thermal radiation regulator, the high surface state density of semimetal can be utilized to enhance the radiation heat flow and the energy utilization rate, and the purpose of regulating near-field thermal radiation can be achieved by regulating the adjustable distance.

Description

Technical Field

[0001] The present invention relates to the technical field of near-field thermal radiation, and more specifically, to a near-field thermal radiation regulator based on semi-metal and a method for regulating radiation heat flux thereof. Background Art

[0002] Thermal radiation, generated by the thermal motion of microscopic particles inside an object and propagating in the form of electromagnetic waves, is one of the three basic ways of heat transfer. The absorptivity, reflectivity and transmittance of different objects in nature vary greatly due to different specific conditions, which brings great difficulties to the study of thermal radiation. For convenience, people started from ideal objects and proposed concepts such as black bodies with an absorptivity of 1, mirror bodies with a reflectivity of r = 1, and transparent bodies with a transmittance of t = 1. Historically, people have conducted in-depth research on the thermal radiation ability of black bodies and proposed three basic laws of black body radiation: Stefan-Boltzmann law, Planck law and Lambert law, which respectively describe the radiation force, spectral radiation force and radiation force distributed in spatial direction of black bodies. In the study of thermal radiation, people often use black bodies as standard objects and study the radiation characteristics of actual objects based on the comparison with the radiation characteristics of black bodies.

[0003] Near-field thermal radiation, relative to far-field thermal radiation, refers to the radiation heat transfer when the distance between objects of different temperatures in the system is less than the thermal characteristic wavelength. The thermal radiation intensity under near-field conditions is significantly greater than that of far-field thermal radiation, and can break the Planck limit in certain frequency bands. In research, people attribute this radiation enhancement to the influence of evanescent waves and special photon propagation modes. In recent decades, theoretical research on active near-field radiation control has made great progress, but limited by existing technology, experimental research has just started. Based on materials with different optical responses, such as two-dimensional materials, phase change materials, magneto-optical materials and metamaterials, people design micro-nano structures such as plate-plate, ball-plate, tip-plate and grating to control near-field thermal radiation. The control of radiation heat flux and radiation energy conversion efficiency under near-field conditions has a wide range of applications in thermophotovoltaic systems, radiation cooling, thermal imaging, thermally assisted magnetic recorders, etc.

[0004] Existing technologies increase near-field thermal radiation by optimizing multilayer structures to enhance surface state coupling, applying external magnetic fields to magneto-optical materials to regulate electromagnetic surface waves and induce hyperbolic modes, etc., but this method makes it difficult to precisely control the radiation heat flow. Summary of the invention

[0005] In order to overcome the defect of the above-mentioned prior art that the radiant heat flux cannot be accurately controlled, the present invention provides a semi-metal-based near-field thermal radiation controller and a radiant heat flux control method thereof that can accurately control the radiant heat flux.

[0006] In order to solve the above technical problems, the semi-metal-based near-field thermal radiation regulator of the present invention includes an emitter and a receiver;

[0007] Wherein, the emitter comprises a first semi-metal layer, a first dielectric layer, and a second semi-metal layer in sequence;

[0008] The receiver includes a third half-metal layer, a second dielectric layer and a fourth half-metal layer in sequence;

[0009] The second half-metal layer and the third half-metal layer are arranged opposite to each other, and there is an adjustable distance between the second half-metal layer and the third half-metal layer.

[0010] The present invention also proposes a method for controlling the radiation heat flux of a near-field thermal radiation controller, which is implemented based on the above-mentioned semi-metal-based near-field thermal radiation controller. The method includes the following steps:

[0011] A simulation model of the near-field thermal radiation regulator is constructed in a simulation platform, and initial values ​​of the thicknesses h1, h3, h4 and h6 of the first, second, third and fourth half-metal layers are set; initial values ​​of the thicknesses h2 and h5 of the first and second dielectric layers are set; and an initial value of the torsion angle α and a distance d between the second half-metal layer and the third half-metal layer are set; wherein the torsion angle α represents the angle formed by the emitter rotating clockwise or counterclockwise around the normal of the center point of the surface of the second half-metal layer starting from the initial position, and when the vertical projection of the emitter coincides with the vertical projection of the receiver, the emitter is at the initial position;

[0012] The objective function is to minimize the difference between the radiation heat flux of the near-field thermal radiation controller and the target radiation heat flux;

[0013] The spacing d, torsion angle α, and thicknesses h1, h2, h3, h4, h5 and h6 are set as variables of the objective function, and the initial value and the objective function are input into the objective optimization algorithm. The objective function is iteratively solved using the objective optimization algorithm. When the number of iterations reaches a preset value, or when the objective function reaches a minimum value, the calculation is terminated to obtain the spacing d, torsion angle α, and thicknesses h1, h2, h3, h4, h5 and h6 that enable the near-field thermal radiation controller to output a target radiation heat flux.

[0014] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0015] The near-field thermal radiation regulator of the present invention utilizes the unique electronic structure of semi-metals to generate non-reciprocal electromagnetic surface waves without relying on an external magnetic field, and utilizes the high surface state density of semi-metals to enhance the radiation heat flow and energy utilization rate; in addition, by regulating the adjustable spacing between the second semi-metal layer and the third semi-metal layer, the purpose of regulating near-field thermal radiation can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of the semi-metal-based near-field thermal radiation regulator proposed in Example 1;

[0017] Figure 2 A schematic diagram of the process of the radiation heat flux control method of the near-field thermal radiation controller proposed in Example 2;

[0018] Figure 3 This is a schematic diagram of the relationship between chemical potential and temperature proposed in Example 3;

[0019] Figure 4 This is a schematic diagram of the first type of total radiation heat flux and radiation spectrum heat flux proposed in Example 3;

[0020] Figure 5 A schematic diagram of the spectral heat flow and energy transfer coefficient proposed in Example 3;

[0021] Figure 6 This is a schematic diagram of the second type of total radiation heat flux and radiation spectrum heat flux proposed in Example 3;

[0022] Figure 7 This is a schematic diagram of the third type of total radiation heat flux and radiation spectrum heat flux proposed in Example 3. DETAILED DESCRIPTION

[0023] The accompanying drawings are only used for illustrative purposes and should not be construed as limiting the present embodiment;

[0024] In order to better illustrate the present embodiment, some parts in the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product;

[0025] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0026] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] Example 1

[0028] This embodiment proposes a near-field thermal radiation controller based on semi-metal. Figure 1 is a schematic structural diagram of a semi-metal-based near-field thermal radiation regulator of this embodiment;

[0029] The semi-metal-based near-field thermal radiation controller proposed in this embodiment includes an emitter and a receiver;

[0030] Wherein, the emitter comprises a first semi-metal layer, a first dielectric layer, and a second semi-metal layer in sequence;

[0031] The receiver includes a third half-metal layer, a second dielectric layer and a fourth half-metal layer in sequence;

[0032] The second half-metal layer and the third half-metal layer are arranged opposite to each other, and there is an adjustable distance between the second half-metal layer and the third half-metal layer.

[0033] In the specific implementation process, the near-field thermal radiation regulator utilizes the unique electronic structure of semi-metals to generate non-reciprocal electromagnetic surface waves without relying on an external magnetic field, and utilizes the high surface state density of semi-metals to enhance the radiation heat flow and energy utilization rate; in addition, by regulating the adjustable spacing between the second semi-metal layer and the third semi-metal layer, the purpose of regulating near-field thermal radiation can be achieved.

[0034] In an optional embodiment, the semi-metals of the first, second, third and fourth semi-metal layers are all Weyl semi-metals.

[0035] As an example, Figure 1 1 represents the first half-metal layer, 2 represents the first dielectric layer, 3 represents the second half-metal layer, 4 represents the third half-metal layer, 5 represents the second dielectric layer, and 6 represents the fourth half-metal layer; wherein the temperature of the emitter is T1, the temperature of the receiver is T2, and T1>T2; the emitter and the receiver are separated by an air layer, that is, the second half-metal layer and the third half-metal layer are separated by an air layer. Figure 1 In the figure, the adjustable distance between the second half-metal layer and the third half-metal layer is represented by d.

[0036] As an example, Figure 1 As shown, the semimetals of the first, second, third and fourth semimetal layers are all Weyl semimetals, and the dielectrics of the first and second dielectric layers are both TiO2 (titanium dioxide).

[0037] As an example, Weyl semimetals can break time reversal symmetry without applying an external magnetic field; and pairs of Weyl points appear in the electronic band structure of Weyl semimetals, and each pair of Weyl points has opposite chirality; this opposite chirality characteristic causes Weyl semimetals to exhibit many interesting phenomena, such as the intrinsic anomalous Hall effect, which leads to the presence of large off-diagonal elements in the dielectric tensor of Weyl semimetals.

[0038] As an exemplary illustration, in view of the excellent properties of Weyl semimetals, the present application designs the following Figure 1 The three-layer symmetrical near-field thermal radiation structure based on Weyl semimetal is shown; among them, the Weyl semimetal with the simplest electronic band structure is selected, that is, the material with only two Weyl points.

[0039] In an optional embodiment, the expression of the dielectric tensor of the Weyl semimetal includes:

[0040]

[0041] α∈[0°,360°)

[0042] In the formula, The dielectric tensor of the Weyl semimetal representing the emitter; represents the dielectric tensor of the Weyl semimetal of the receiver; ε d express and The main diagonal elements of a express and The non-main diagonal elements of ; 2b represents the distance between two Weyl points of the Weyl semimetal; e represents the elementary charge; represents the reduced Planck tensor; ω represents the angular frequency of the near-field thermal radiation controller; ε b represents the background dielectric constant; σ represents the bulk conductivity of the Weyl semimetal; α represents the torsion angle, wherein the torsion angle α represents the angle formed by rotating the emitter clockwise or counterclockwise around the normal line of the center point of the surface of the second semimetal layer starting from the initial position. When the vertical projection of the emitter coincides with the vertical projection of the receiver, the emitter is at the initial position.

[0043] As an example, the expression for bulk conductivity σ includes:

[0044]

[0045] In an optional embodiment, the expression of the radiation heat flux of the near-field thermal radiation regulator includes:

[0046]

[0047] Wherein, J represents the radiation heat flux of the near-field thermal radiation controller; N1 represents the Bose-Einstein distribution corresponding to the emitter; N2 represents the Bose-Einstein distribution corresponding to the receiver; β represents the in-plane wave vector; ω represents the angular frequency of the near-field thermal radiation controller; represents the reduced Planck constant; φ represents the azimuth; ξ(ω,β,φ) represents the energy transfer coefficient.

[0048] As an exemplary illustration, the energy transfer coefficient is also called the photon tunneling probability; the azimuth angle is also called the incident light azimuth angle or longitude angle.

[0049] As an example, the expression for the Bose–Einstein distribution includes:

[0050]

[0051] Where N 1,2 Indicates N1 or N2. When the subscript 1 is removed, it indicates N1, and when the subscript 2 is removed, it indicates N2; T 1,2 Indicates the temperature of the emitter or receiver. When the subscript 1 is removed, it indicates the temperature of the emitter T1. When the subscript 2 is removed, it indicates the temperature of the receiver T2.

[0052] In an optional embodiment, the expression of the energy transfer coefficient ξ(ω, β, φ) includes:

[0053]

[0054] Where Tr[·] means finding the trace of the matrix; I means the identity matrix; represents conjugate transpose; D represents a Fabry-Perot-like matrix; e2 represents a natural constant; β0 represents an out-of-plane normal wave vector; d represents the spacing between the second half-metal layer and the third half-metal layer; β represents an in-plane wave vector; k0 represents a wave vector of light in a vacuum; R1 represents a reflection coefficient matrix of the emitter; and R2 represents a reflection coefficient matrix of the receiver.

[0055] As an example, In the formula, i represents an imaginary number.

[0056] As an example, the expression of the reflection coefficient matrix includes:

[0057]

[0058] In the formula, R 1,2 Represents R1 or R2, and its elements represent the reflection coefficient of the material for s-polarized plane waves and p-polarized plane waves incident from the air, reflecting the optical properties of the material itself and having nothing to do with the incident light; as an exemplary illustration, the reflection coefficient matrix is ​​calculated using the transmission matrix method.

[0059] In an optional embodiment, the thickness of the first half-metal layer is the same as the thickness of the fourth half-metal layer, the thickness of the second half-metal layer is the same as the thickness of the third half-metal layer, the thickness of the first dielectric layer is the same as the thickness of the second dielectric layer, and the thickness of the first, second, third and fourth half-metal layers are adjustable, and the thickness of the first and second dielectric layers are adjustable.

[0060] Example 2

[0061] This embodiment proposes a method for controlling the radiation heat flux of a near-field thermal radiation controller, which is implemented based on the semi-metal-based near-field thermal radiation controller proposed in Example 1.

[0062] Figure 2 This is a schematic flow chart of the radiation heat flux control method of the near-field thermal radiation controller proposed in this embodiment.

[0063] The method for controlling the radiation heat flux of the near-field thermal radiation controller comprises the following steps:

[0064] S1: constructing a simulation model of the near-field thermal radiation regulator in a simulation platform, setting the initial values ​​of the thicknesses h1, h3, h4 and h6 of the first, second, third and fourth half-metal layers; setting the initial values ​​of the thicknesses h2 and h5 of the first and second dielectric layers; setting the torsion angle α, and the initial value of the spacing d between the second half-metal layer and the third half-metal layer; wherein the torsion angle α represents the angle formed by the emitter rotating clockwise or counterclockwise around the normal of the center point of the surface of the second half-metal layer starting from the initial position, and when the vertical projection of the emitter coincides with the vertical projection of the receiver, the emitter is at the initial position;

[0065] S2: Taking the difference between the radiation heat flux of the near-field thermal radiation controller and the target radiation heat flux as the objective function;

[0066] S3: The spacing d, torsion angle α, and thicknesses h1, h2, h3, h4, h5 and h6 are set as variables of the objective function, and the initial value and the objective function are input into the objective optimization algorithm. The objective function is iteratively solved using the objective optimization algorithm. When the number of iterations reaches a preset value, or the objective function reaches a minimum value, the calculation is terminated to obtain the spacing d, torsion angle α, and thicknesses h1, h2, h3, h4, h5 and h6 that enable the near-field thermal radiation controller to output the target radiation heat flux.

[0067] As an exemplary illustration, while keeping the chemical potential, Fermi velocity, Weyl point spacing and other parameters of the material unchanged, by changing the thickness of the Weyl layer of the structure, the distance of the air spacer layer, the orientation of the Weyl point spacing, etc., the effect of these parameters on the regulation of the near-field radiation heat flux is observed, so as to find the optimal heat flux regulation structure to meet the needs of practical applications.

[0068] In an optional embodiment, the expression of the objective function includes:

[0069]

[0070] Where, J represents the radiation heat flux of the near-field thermal radiation controller; J g represents the preset target radiation heat flux; N1 represents the Bose-Einstein distribution corresponding to the emitter; N2 represents the Bose-Einstein distribution corresponding to the receiver; β represents the in-plane wave vector; ω represents the angular frequency of the near-field thermal radiation regulator; represents the reduced Planck constant; α represents the torsion angle; ξ(ω,β,φ) represents the energy transfer coefficient; Tr[·] represents the trace of the matrix; I represents the identity matrix; represents conjugate transpose; D represents a Fabry-Perot-like matrix; e2 represents a natural constant; β0 represents an out-of-plane normal wave vector; d represents the spacing between the second half-metal layer and the third half-metal layer; β represents an in-plane wave vector; k0 represents a wave vector of light in a vacuum; R1 represents a reflection coefficient matrix of the emitter; and R2 represents a reflection coefficient matrix of the receiver.

[0071] In an optional embodiment, the calculation step of the reflection coefficient matrix R1 includes:

[0072] The dielectric tensor Substitute the Maxwell equations into the first partial differential equations to obtain the first partial differential equations; according to the method for solving the first partial differential equations, the form of the wave function in the emitter is given S(z, h1, h2, h3), wherein z represents a spatial variable, and the electromagnetic wave is decomposed into a transverse electric wave and a transverse magnetic wave, and the boundary conditions of the electromagnetic wave are constructed based on the transverse electric wave and the transverse magnetic wave, and the reflection coefficient matrix R1 is solved using the boundary conditions of the electromagnetic wave;

[0073] The calculation steps of the reflection coefficient matrix R2 include:

[0074] The dielectric tensor Substitute the Maxwell equations into the second group of partial differential equations to obtain; according to the method of solving the second group of partial differential equations, the form of the wave function S(z, h4, h5, h6) in the emitter is given, and the electromagnetic wave is decomposed into transverse electric wave and transverse magnetic wave, and the boundary conditions of the electromagnetic wave are constructed based on the transverse electric wave and transverse magnetic wave. Using the boundary conditions of the electromagnetic wave, the reflection coefficient matrix R2 is solved.

[0075] It can be understood that the radiation heat flux control method of the near-field thermal radiation controller of this embodiment is implemented based on the near-field thermal radiation controller of Example 1. The options in the above-mentioned Example 1 are also applicable to this embodiment, so they will not be repeated here.

[0076] This embodiment proposes a computer device, including a memory and a processor, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the processor executes the steps of the radiation heat flow control method of the near-field thermal radiation controller described in Example 2.

[0077] It can be understood that the computer device of this embodiment improves the method of Example 2, and the options in the above-mentioned Example 2 are also applicable to this embodiment, so they are not described repeatedly here.

[0078] Example 3

[0079] This embodiment proposes specific parameter settings of a semi-metal-based near-field thermal radiation regulator and a specific implementation example of the radiation heat flux regulation method.

[0080] Figure 3 A schematic diagram showing the relationship between chemical potential and temperature proposed in this embodiment; Figure 4 A schematic diagram of the first type of total radiation heat flow and radiation spectrum heat flow proposed in this embodiment; Figure 5 A schematic diagram of the spectral heat flow and energy transfer coefficient proposed in this embodiment; Figure 6 A schematic diagram of the second type of total radiation heat flow and radiation spectrum heat flow proposed in this embodiment; Figure 7 This is a schematic diagram of the third type of total radiation heat flux and radiation spectrum heat flux proposed in this embodiment.

[0081] The parameters of the near-field thermal radiation controller are specifically designed so that the thickness h1 of the first half-metal layer is the same as the thickness h6 of the fourth half-metal layer, the thickness h3 of the second half-metal layer is the same as the thickness h4 of the third half-metal layer, and the thickness h2 of the first dielectric layer is the same as the thickness h5 of the second dielectric layer.

[0082] Let the background dielectric constant ε b =6.2, cut-off energy E c =3, relaxation time τ = 1000 fs, number of Weyl points g = 2, half of the Weyl point interval b = 2 × 10m-1 , Fermi speed v F =0.83×10 5 m / s. The chemical potential E F is a function of temperature, and its relationship with temperature is as follows Figure 3 Of course, the chemical potential is also affected by factors such as doping concentration and voltage bias. In the present invention, although the emitter temperature T1 = 300K and the receiver temperature T2 = 0K are not equal, the chemical potential of the Weyl semimetal is uniformly set to E F =0.16eV. The central layer of the sandwich structure is TiO2, and its relative dielectric constant ε r =5.0625.

[0083] We simultaneously change the thickness of the four Weyl semimetal layers in the structure to 10nm, 15nm, 20nm, 25nm, 30nm, and 35nm. The air layer spacing remains unchanged at d = 20nm. The total heat flux and spectral heat flux of thermal radiation are shown in Figure 4 As shown, Figure 4 The (a) total radiation heat flux and (b) radiation spectrum heat flux are shown when the thickness of the air spacer layer d = 20nm is kept constant and the thickness of each layer of the emitter and receiver h1, h2, h3 are changed.

[0084] from Figure 4 From the total heat flow in part (a), we can see that as the thickness of the Weyl semimetal increases, the total heat flow is decreasing, which is consistent with the trend that the spectral heat flow decreases with increasing thickness. In the frequency band of 0.11-0.14eV, it can be clearly seen that as the thickness increases, the radiation peak in this frequency band not only gradually disappears, but also the peak position is accompanied by red shift in the process of gradually weakening. This phenomenon allows us to control the intensity and frequency of thermal radiation at this frequency by changing the thickness of the Weyl layer.

[0085] Figure 5 The following diagram shows (a) spectral heat flow when h1 = h2 = h3 = 10 nm and d = 20 nm; (b) energy transfer coefficient when ω = 0.06707 eV; (c) energy transfer coefficient when ω = 0.1359 eV; (d) energy transfer coefficient when ω = 0.151. In particular, under the structural parameters of layer thickness h1 = h2 = h3 = 10 nm, the spectral heat flow has three radiation peaks, i.e., with two radiation valleys, such as Figure 5 We selected three peak frequencies and calculated their energy transfer coefficients, as shown in part (a) of Figure 5 As shown in parts (b), (c) and (d) of .

[0086] The energy transfer coefficient of ω=0.06707eV is in the wave vector k x , ky It has a circular shape in space; it has an elliptical shape when ω = 0.1359 eV; and it has a hyperbolic shape when ω = 0.151 eV. Figure 5 Part (c) of Figure 5 In part (d), the wave vector k in the x-axis direction x ∈[0,50], and the wave vector k in the y-axis direction y ∈[0,300], k y The value range is much larger than k x , indicating that there are more k y Directional propagation mode.

[0087] Figure 6 It shows (a) the total radiation heat flux and (b) the radiation spectrum heat flux under different air spacer thicknesses while the thickness of each layer of the emitter and receiver (h1=h2=h3=10nm) remains unchanged.

[0088] Next, we keep the thickness of the Weyl semimetal layer (h1 = h2 = h3 = 10nm) unchanged, and the thickness of the air spacer layer d is 10nm, 15nm, 20nm, 25nm, 30nm, 35nm respectively. The total heat flux and spectral heat flux of thermal radiation are as follows: Figure 6 (a) and (b) show that, when other conditions remain unchanged, as the thickness of the air gap layer increases, the total radiation heat flux gradually decreases, and the total radiation heat flux is inversely proportional to the thickness of the air gap layer.

[0089] Figure 7 The (a) total radiation heat flux and (b) radiation spectrum heat flux at different twist angles α are shown when the thickness of the emitter and receiver is h1=h2=h3=10nm and the thickness of the air spacer layer is d=20nm.

[0090] Finally, we keep the thickness of the emitter and receiver h1 = h2 = h3 = 10nm and the thickness of the air spacer d = 20nm unchanged, and change the torsion angle (i.e. the angle between 2b and the y-axis). The total radiation heat flux and spectral heat flux are as follows: Figure 7 shown.

[0091] Depend on Figure 7 (a) We can find that the total radiation heat flux has a symmetrical distribution characteristic with respect to the torsion angle. Figure 7(b) shows the spectral radiation heat flux in the range of 0° to 90°. It can be found that as the twist angle gradually increases from 0° to 90°, the overall spectral radiation heat flux gradually decreases, especially for the high-frequency part, such as the spectral radiation heat flux in the frequency range of 0.12 to 0.15 eV. From this, we can infer that the trend of the total radiation heat flux decreasing with the increase of the twist angle is mainly caused by the suppression of the high-frequency part of the spectral radiation heat flux as the twist angle increases.

[0092] In this optional embodiment, the thermal radiation structure has the characteristics of simple structure compared with more layer structures, and also meets the requirements for regulating the total radiation heat flux and the spectral radiation heat flux at different frequencies. Compared with the single-layer symmetrical structure, the regulation effect of the spectral radiation heat flux of this structure is more obvious. When the thickness of each layer of the Weyl / TiO2 / Weyl three-layer structure is 10nm, three radiation peaks appear in the spectral radiation heat flux, reflecting the excellent mid-infrared multi-band regulation performance; when the thickness of the air spacer layer is as small as 10nm, it can be found that the radiation heat flux of the structure is significantly enhanced, especially near 0.15eV; when the torsion angle is changed, the total radiation heat flux has angular symmetry, and the total radiation heat flux is the smallest when the torsion angle between the emitter and the receiver differs by 90°. The mismatch of the torsion angle can better suppress the radiation of the high-frequency part. Among them, the three-layer symmetrical thermal radiation structure with Weyl / TiO2 / Weyl layer and air spacer layer thickness, especially when the thickness of each Weyl / TiO2 / Weyl layer is 10nm and the thickness of the air spacer layer is 20nm, the spectral radiation heat flux of the structure shows three radiation peaks, showing excellent thermal radiation regulation performance; revealing the influence of changing the orientation of the Weyl gap 2b of the emitter or receiver, that is, the torsion angle, on the thermal radiation: the mismatch of the torsion angle causes the total radiation heat flux to decrease, and the total radiation heat flux is symmetrically distributed with respect to the torsion angle; the spectral radiation heat flux in the high-frequency part is more susceptible to changes in the torsion angle.

[0093] The same or similar reference numerals correspond to the same or similar components;

[0094] The terms used to describe the positional relationship in the drawings are only used for illustrative purposes and should not be construed as limiting the present embodiment;

[0095] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A near-field thermal radiation controller based on semi-metal, characterized in that: It includes a transmitter and a receiver; Wherein, the emitter comprises a first semi-metal layer, a first dielectric layer, and a second semi-metal layer in sequence; The receiver includes a third half-metal layer, a second dielectric layer and a fourth half-metal layer in sequence; The second half-metal layer and the third half-metal layer are arranged opposite to each other, and there is an adjustable distance between the second half-metal layer and the third half-metal layer.

2. The semi-metal-based near-field thermal radiation controller according to claim 1, characterized in that: The semimetals of the first, second, third and fourth semimetal layers are all Weyl semimetals.

3. The semi-metal-based near-field thermal radiation controller according to claim 2, characterized in that: The expression for the dielectric tensor of the Weyl semimetal includes: α∈[0°,360°) In the formula, The dielectric tensor of the Weyl semimetal representing the emitter; represents the dielectric tensor of the Weyl semimetal of the receiver; ε d express and The main diagonal elements of a express and The non-main diagonal elements of ; 2b represents the distance between two Weyl points of the Weyl semimetal; e represents the elementary charge; represents the reduced Planck tensor; ω represents the angular frequency of the near-field thermal radiation controller; ε b represents the background dielectric constant; σ represents the bulk conductivity of the Weyl semimetal; α represents the torsion angle, wherein the torsion angle α represents the angle formed by rotating the emitter clockwise or counterclockwise around the normal line of the center point of the surface of the second semimetal layer starting from the initial position. When the vertical projection of the emitter coincides with the vertical projection of the receiver, the emitter is at the initial position.

4. The semi-metal-based near-field thermal radiation controller according to claim 3, characterized in that: The expression of the radiation heat flux of the near-field thermal radiation controller includes: Wherein, J represents the radiation heat flux of the near-field thermal radiation controller; N1 represents the Bose-Einstein distribution corresponding to the emitter; N2 represents the Bose-Einstein distribution corresponding to the receiver; β represents the in-plane wave vector; ω represents the angular frequency of the near-field thermal radiation controller; represents the reduced Planck constant; φ represents the azimuth; ξ(ω,β,φ) represents the energy transfer coefficient.

5. The semi-metal-based near-field thermal radiation controller according to claim 4, characterized in that: The expression of the energy transfer coefficient ξ(ω, β, φ) includes: Where Tr[·] means finding the trace of the matrix; I means the identity matrix; represents conjugate transpose; D represents a Fabry-Perot-like matrix; e2 represents a natural constant; β0 represents an out-of-plane normal wave vector; d represents the spacing between the second half-metal layer and the third half-metal layer; β represents an in-plane wave vector; k0 represents a wave vector of light in a vacuum; R1 represents a reflection coefficient matrix of the emitter; and R2 represents a reflection coefficient matrix of the receiver.

6. The semi-metal-based near-field thermal radiation controller according to any one of claims 1 to 5, characterized in that: The thickness of the first half-metal layer is the same as the thickness of the fourth half-metal layer, the thickness of the second half-metal layer is the same as the thickness of the third half-metal layer, the thickness of the first dielectric layer is the same as the thickness of the second dielectric layer, and the thickness of the first, second, third and fourth half-metal layers are adjustable, and the thickness of the first and second dielectric layers are adjustable.

7. A method for controlling the radiation heat flux of a near-field thermal radiation controller, the method being implemented based on the semi-metal-based near-field thermal radiation controller according to any one of claims 1 to 6, characterized in that: The following steps are involved: A simulation model of the near-field thermal radiation regulator is constructed in a simulation platform, and initial values ​​of the thicknesses h1, h3, h4 and h6 of the first, second, third and fourth half-metal layers are set; initial values ​​of the thicknesses h2 and h5 of the first and second dielectric layers are set; and an initial value of the torsion angle α and a distance d between the second half-metal layer and the third half-metal layer are set; wherein the torsion angle α represents the angle formed by the emitter rotating clockwise or counterclockwise around the normal of the center point of the surface of the second half-metal layer starting from the initial position, and when the vertical projection of the emitter coincides with the vertical projection of the receiver, the emitter is at the initial position; The objective function is to minimize the difference between the radiation heat flux of the near-field thermal radiation controller and the target radiation heat flux; The spacing d, torsion angle α, and thicknesses h1, h2, h3, h4, h5 and h6 are set as variables of the objective function, and the initial value and the objective function are input into the objective optimization algorithm. The objective function is iteratively solved using the objective optimization algorithm. When the number of iterations reaches a preset value, or when the objective function reaches a minimum value, the calculation is terminated to obtain the spacing d, torsion angle α, and thicknesses h1, h2, h3, h4, h5 and h6 that enable the near-field thermal radiation controller to output a target radiation heat flux.

8. The method for controlling the radiation heat flux of a near-field thermal radiation controller according to claim 7, characterized in that: The expression of the objective function includes: Where, J represents the radiation heat flux of the near-field thermal radiation controller; J g represents the preset target radiation heat flux; N1 represents the Bose-Einstein distribution corresponding to the emitter; N2 represents the Bose-Einstein distribution corresponding to the receiver; β represents the in-plane wave vector; ω represents the angular frequency of the near-field thermal radiation regulator; represents the reduced Planck constant; α represents the torsion angle; ξ(ω,β,φ) represents the energy transfer coefficient; Tr[·] represents the trace of the matrix; I represents the identity matrix; represents conjugate transpose; D represents a Fabry-Perot-like matrix; e2 represents a natural constant; β0 represents an out-of-plane normal wave vector; d represents the spacing between the second half-metal layer and the third half-metal layer; β represents an in-plane wave vector; k0 represents a wave vector of light in a vacuum; R1 represents a reflection coefficient matrix of the emitter; and R2 represents a reflection coefficient matrix of the receiver.

9. The method for controlling the radiation heat flux of a near-field thermal radiation controller according to claim 7, characterized in that: The calculation steps of the reflection coefficient matrix R1 include: The dielectric tensor Substitute the Maxwell equations into the first partial differential equations to obtain the first partial differential equations; according to the method for solving the first partial differential equations, the form of the wave function in the emitter is given S(z, h1, h2, h3), wherein z represents a spatial variable, and the electromagnetic wave is decomposed into a transverse electric wave and a transverse magnetic wave, and the boundary conditions of the electromagnetic wave are constructed based on the transverse electric wave and the transverse magnetic wave, and the reflection coefficient matrix R1 is solved using the boundary conditions of the electromagnetic wave; The calculation steps of the reflection coefficient matrix R2 include: The dielectric tensor Substitute the Maxwell equations into the second group of partial differential equations to obtain; according to the method of solving the second group of partial differential equations, the form of the wave function S(z, h4, h5, h6) in the emitter is given, and the electromagnetic wave is decomposed into transverse electric wave and transverse magnetic wave, and the boundary conditions of the electromagnetic wave are constructed based on the transverse electric wave and transverse magnetic wave. Using the boundary conditions of the electromagnetic wave, the reflection coefficient matrix R2 is solved.

10. A computer device comprising a memory and a processor, wherein the memory stores computer-readable instructions, characterized in that: When the computer-readable instructions are executed by the processor, the processor executes the steps of the method for controlling the radiation heat flux of a near-field thermal radiation regulator according to any one of claims 7 to 9.

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