Photon routing method and system based on giant atom-cavity-waveguide, and storage medium

Abstract

The invention discloses a giant atom-cavity-waveguide-based photon routing method and system and a storage medium. The method comprises the following steps: establishing a giant atom-cavity-waveguide waveguide QED system model; calculating a giant atom-cavity-waveguide system momentum equation; calculating a transmissivity expression of the photons incident from the left side according to the momentum equation; calculating a transmissivity expression of the photons incident from the right side according to the momentum equation; and a contrast function is calculated according to the transmissivity of incidence in different directions, and the parameters of the giant atom-cavity-waveguide system are modulated according to the contrast function, so that non-reciprocity photon routing is realized. According to the invention, the problem of poor single-photon non-reciprocal scattering performance caused by fast photon attenuation and limited coupling strength in a giant atom direct coupling mode is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of quantum communication, and particularly relates to a photon routing method, system, and storage medium based on a giant atom-cavity-waveguide. Background Art

[0002] The waveguide QED system utilizes the strong interaction between single photons in a waveguide and emitters, and has the advantages of long transmission distance, high scattering efficiency, etc., and has great potential in realizing quantum communication and quantum information processing. In the waveguide QED system, the strong light-matter interaction enables the non-reciprocal scattering behavior of single photons, and has begun to be applied to the design of high-contrast quantum non-reciprocal devices. However, most current studies focus on the case of point emitters, relying on the local coupling between the emitter and the waveguide and a simple phase modulation mechanism.

[0003] When the size of the emitter is comparable to the wavelength of photons in the waveguide, the point emitter model and the dipole approximation are no longer applicable. At this time, a giant atom model is needed to describe the interaction between the emitter and the waveguide. The giant atom can interact with the waveguide through multiple coupling points, generating a unique phase-dependent interference effect, resulting in a series of peculiar quantum phenomena, including frequency-dependent Lamb shift, non-exponential decay, and decoherence-free interaction, etc. Based on these characteristics, the giant atom has important application potential in non-reciprocity research. Although the giant atom exhibits rich physical phenomena and potential applications in the waveguide QED system, the direct coupling mode has problems such as fast photon decay and limited coupling strength.

[0004] In order to solve the problem that the direct coupling mode of the giant atom has fast photon decay and limited coupling strength, resulting in poor single-photon non-reciprocal scattering performance, a photon routing method, system, and storage medium based on a giant atom-cavity-waveguide are proposed. Summary of the Invention

[0005] An embodiment of the present invention proposes a photon routing method, system, and storage medium based on a giant atom-cavity-waveguide, so as to at least solve the problem that the direct coupling mode of the giant atom has fast photon decay and limited coupling strength, resulting in poor single-photon non-reciprocal scattering performance.

[0006] Non-reciprocity means that the response of the system is different when photons are incident on the system from different directions, which is also called non-reciprocal transmission of the optical field. Using non-reciprocity can effectively avoid the influence of the reflected optical field of other devices or systems on the signal source, etc.

[0007] According to an embodiment of the present invention, a photon routing method based on a giant atom-cavity-waveguide is proposed, including:

[0008] Establishing a waveguide QED system model of a giant atom-cavity-waveguide;

[0009] Calculate the system momentum equation of the giant atom-cavity-waveguide;

[0010] Calculate the transmittance expression of photons incident from the left according to the momentum equation;

[0011] Calculate the transmittance expression of photons incident from the right according to the momentum equation;

[0012] Calculate the contrast function based on the transmittance of photons incident from different directions and modulate the system parameters of the giant atom-cavity-waveguide to achieve non-reciprocal photon routing.

[0013] In an exemplary embodiment, the waveguide QED system model of the giant atom-cavity-waveguide is a giant atom-cavity-waveguide structure in which two cavities are coupled to the same waveguide and a two-level giant atom is coupled to the two cavities.

[0014] In an exemplary embodiment, the calculating the system momentum equation of the giant atom-cavity-waveguide includes the steps of:

[0015] Use the real-space method to calculate the equivalent Hamiltonian of the system;

[0016] Calculate the system momentum equation of the giant atom-cavity-waveguide according to the equivalent Hamiltonian.

[0017] In an exemplary embodiment, the using the real-space method to calculate the equivalent Hamiltonian of the system includes the steps of:

[0018] Calculate the free Hamiltonian of the giant atom according to the resonant frequency of the giant atom and the dissipation of the giant atom;

[0019] Calculate the free Hamiltonian of the two cavities according to the resonant frequencies of the two cavities, the dissipations of the two cavities, the creation operators of the two cavities, and the annihilation operators of the two cavities;

[0020] Calculate the Hamiltonian of the waveguide according to the group velocity of photons propagating in the waveguide, the bosonic creation operator of light, and the bosonic annihilation operator of light;

[0021] Calculate the Hamiltonian of the interaction between the waveguide and the cavity according to the interaction strength of the two cavities coupled to the waveguide;

[0022] Calculate the Hamiltonian of the interaction between the giant atom and the cavity according to the coupling strength of the two-level giant atom coupled to the two cavities.

[0023] In an exemplary embodiment, the calculating the system momentum equation of the giant atom-cavity-waveguide according to the equivalent Hamiltonian includes the steps of:

[0024] Calculate the eigenstate in the single-exciton cavity-waveguide space according to the probability amplitude of photons propagating to the right or left in the waveguide, the excitation amplitude of the cavity mode, and the excitation amplitude of the giant atom;

[0025] The system momentum equation of the giant atom-cavity-waveguide is obtained by solving the conventional Schrödinger equation.

[0026] In an exemplary embodiment, calculating the transmittance expression of photons incident from the left according to the momentum equation includes the steps of:

[0027] Calculating the wave function expression of a single photon incident from the left end of the waveguide that satisfies the linear dispersion relation;

[0028] When the photon reaches the coupling point of the cavity and the waveguide, the incident photon is transmitted or reflected according to the interaction between the waveguide and the cavity-giant atom;

[0029] Calculating the transmittance expression of photons incident from the left according to the system momentum equation of the giant atom-cavity-waveguide.

[0030] In an exemplary embodiment, calculating the transmittance expression of photons incident from the right according to the momentum equation includes the steps of:

[0031] Calculating the wave function expression of a single photon incident from the right end of the waveguide that satisfies the linear dispersion relation;

[0032] When the photon reaches the coupling point of the cavity and the waveguide, calculating the transmittance expression of photons incident from the right according to the system momentum equation of the giant atom-cavity-waveguide.

[0033] In an exemplary embodiment, calculating the contrast function based on the transmittance of photons incident in different directions and modulating the system parameters of the giant atom-cavity-waveguide to achieve non-reciprocal photon routing includes the steps of:

[0034] Calculating the contrast function according to the transmittance of photons incident from the left and the transmittance of photons incident from the right;

[0035] Simplifying the contrast function according to the interactions between two cavities and the waveguide, the interactions between two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavity;

[0036] Modulating the interactions between two cavities and the waveguide, the interactions between two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavity so that the value of the simplified contrast function is maximized;

[0037] Adjusting the system parameters to the interactions between two cavities and the waveguide, the interactions between two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavity when the contrast value is maximized to achieve non-reciprocal photon routing.

[0038] A computer-readable storage medium stores a computer program for electronic data exchange, wherein the computer program causes a computer to execute the above method.

[0039] According to another embodiment of the present invention, a photon routing system based on a giant atom-cavity-waveguide is provided, including:

[0040] A waveguide QED system of a giant atom-cavity-waveguide;

[0041] A processor;

[0042] A memory;

[0043] And

[0044] One or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the processor, and the programs cause the computer to execute the above method.

[0045] The advantages of the photon routing method, system and storage medium based on the giant atom-cavity-waveguide of the present invention are:

[0046] (1) Construct a waveguide QED system of a giant atom-cavity-waveguide. Compared with the traditional technical solution of introducing a cavity structure into the waveguide system of a giant atom, it can not only improve the coupling efficiency of the system, but also increase adjustable parameters, facilitating more complex quantum control.

[0047] (2) By using the equivalent Hamiltonian and the Schrödinger equation, the transmittance expression of photons incident on the waveguide QED system of the giant atom-cavity-waveguide from different directions is solved. Compared with the traditional single-photon transmission modulation method, the dynamic transmission characteristics of single photons in the waveguide QED system of the giant atom-cavity-waveguide based on time-domain modulation can be accurately analyzed.

[0048] (3) According to the momentum equation of the waveguide QED system of a two-atom-two-cavity and the amplitude expression of photons, the transmittance expression of photons is calculated. Compared with the traditional technical solution of single-photon transmission modulation, the influence of atomic frequency time-domain modulation on the transmittance and reflectance of single photons can be effectively analyzed, and the single-photon transmission control based on atomic frequency time-domain modulation can be effectively realized.

[0049] (3) Calculate the contrast function of the transmittance for different incident directions and modulate the system parameters of the giant atom-cavity-waveguide to achieve non-reciprocal photon routing. Compared with the traditional technical solution of single-photon transmission modulation, the non-reciprocal influence factors of the giant atom-cavity-waveguide model can be accurately analyzed, and non-reciprocal photon routing can be effectively realized. Description of the Drawings

[0050] Figure 1 is a flowchart of a photon routing method based on a giant atom-cavity-waveguide according to an embodiment of the present invention;

[0051] Figure 2 is a model diagram of a waveguide QED system of a giant atom-cavity-waveguide;

[0052] Figure 3 is the flowchart of step S02 in the embodiment of the present invention;

[0053] Figure 4 is the flowchart of sub-step S021 in the embodiment of the present invention;

[0054] Figure 5 is the flowchart of sub-step S022 in the embodiment of the present invention;

[0055] Figure 6 is the flowchart of step S03 in the embodiment of the present invention;

[0056] Figure 7 is the flowchart of step S04 in the embodiment of the present invention;

[0057] Figure 8 is the flowchart of sub-step S05 in the embodiment of the present invention;

[0058] Figure 9 is the schematic structural diagram of a photon routing system based on a giant atom-cavity-waveguide in the embodiment of the present invention. Detailed Embodiment

[0059] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the invention, but do not limit the invention in any form. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0060] A photon routing method based on a giant atom-cavity-waveguide in the embodiment of the present invention has a flowchart as Figure 1 shown, including the steps:

[0061] Step S01, establish a waveguide QED system model of a giant atom-cavity-waveguide;

[0062] Step S02, calculate the system momentum equation of a giant atom-cavity-waveguide;

[0063] Step S03, calculate the transmittance expression of photons incident from the left according to the momentum equation;

[0064] Step S04, calculate the transmittance expression of photons incident from the right according to the momentum equation;

[0065] Step S05, calculate the contrast function according to the transmittance of photons incident from different directions and modulate the system parameters of the giant atom-cavity-waveguide to achieve non-reciprocal photon routing.

[0066] Giant atoms exhibit rich physical phenomena and potential applications in waveguide QED systems. However, there are problems such as relatively fast photon decay and limited coupling strength in the direct coupling mode. In this paper, a giant atom-cavity-waveguide model is formed by adding cavity coupling to improve these deficiencies. By controlling the coupling strength between the atom and the waveguide through the cavity, the control precision of the system is improved. Introducing a cavity structure into the giant atom-waveguide system can not only enhance the coupling efficiency of the system but also increase adjustable parameters, providing possibilities for more complex quantum control.

[0067] In an exemplary embodiment, the waveguide QED system model of the giant atom-cavity-waveguide is a giant atom-cavity-waveguide structure in which two cavities are coupled to the same waveguide, and then a two-level giant atom is coupled to the two cavities. In this embodiment, the waveguide QED system model of the giant atom-cavity-waveguide is as Figure 2 shown. The waveguide QED system is composed of cavity A and cavity B coupled to the same waveguide, and the interaction strengths are respectively and The two-level giant atom is coupled to the two cavities, and the coupling strengths are and

[0068] In an exemplary embodiment, for the step S02 of calculating the system momentum equation of the giant atom-cavity-waveguide, the flowchart is as Figure 3 shown, including the steps:

[0069] Step S021: Calculate the equivalent Hamiltonian of the system using the real-space method;

[0070] Step S022: Calculate the system momentum equation of the giant atom-cavity-waveguide according to the equivalent Hamiltonian.

[0071] In an exemplary embodiment, for the step S021 of calculating the equivalent Hamiltonian of the system using the real-space method, the flowchart is as Figure 4 shown, including:

[0072] Step S0211: Calculate the free Hamiltonian of the giant atom according to the resonance frequency of the giant atom and the dissipation of the giant atom;

[0073] Step S0212: Calculate the free Hamiltonian of the two cavities according to the resonance frequencies of the two cavities, the dissipation of the two cavities, the creation operators of the two cavities, and the annihilation operators of the two cavities;

[0074] Step S0213: Calculate the Hamiltonian of the waveguide according to the group velocity of the photon propagating in the waveguide and the bosonic creation operator and bosonic annihilation operator of light;

[0075] Step S0214: Calculate the Hamiltonian of the interaction between the waveguide and the cavity according to the interaction strength of the two cavities coupled to the waveguide;

[0076] Step S0215: Calculate the Hamiltonian of the interaction between the giant atom and the cavity according to the coupling strengths of the two-level giant atom coupled to the two cavities.

[0077] In this embodiment, in this system, the frequency of the atom changes periodically. The real-space method is used to calculate the equivalent Hamiltonian of the giant atom-cavity-waveguide system, which are respectively:

[0078] Calculate the free Hamiltonian of the giant atom according to the resonant frequency of the giant atom and the dissipation of the giant atom, which is expressed as:

[0079]

[0080] where, H a represents the equivalent Hamiltonian of the waveguide, ω e is the resonant frequency of the giant atom, and γ e represents the dissipation of the giant atom.

[0081] Calculate the free Hamiltonian of the two cavities according to the resonant frequencies of the two cavities, the dissipations of the two cavities, the creation operators of the two cavities, and the annihilation operators of the two cavities, which is expressed as:

[0082]

[0083] where, H c represents the free Hamiltonian of the two cavities, ω j (j = a, b) are the resonant frequencies of the two cavities, γ j (j = a, b) are the dissipations of the two cavities, and respectively represent the creation (annihilation) operators of the two cavities.

[0084] Calculate the Hamiltonian of the waveguide according to the group velocity of the photon propagating in the waveguide, the boson creation operator of the light, and the boson annihilation operator of the light, which is expressed as:

[0085]

[0086] where, H w represents the Hamiltonian of the waveguide, υ g is the group velocity of the photon propagating in the waveguide,

[0087] are respectively the boson creation (annihilation) operators of a left-propagating light beam and a right-propagating light beam at the x position.

[0088] Calculate the Hamiltonian of the interaction between the waveguide and the cavity according to the interaction strength of the two cavities coupled to the waveguide, which is expressed as:

[0089]

[0090] Among them, H wc represents the Hamiltonian of the interaction between the waveguide and the cavity, where the interaction strengths of cavity A and cavity B coupled to the waveguide are V a and V b , is the local coupling phase, and H.c. is the corresponding Hermitian conjugate.

[0091] According to the coupling strengths of the two-level giant atom coupled to the two cavities, the Hamiltonian of the interaction between the giant atom and the cavities is calculated and expressed as:

[0092]

[0093] Among them, H ca represents the Hamiltonian of the interaction between the giant atom and the cavities, g a and g b represent the coupling strengths of the two-level giant atom coupled to the two cavities, θ a(b) is the coupling phase between the two, σ m,n＝e,g is the dipole transition operator, and H.c. is the corresponding Hermitian conjugate.

[0094] In an exemplary embodiment, the step S022, calculating the system momentum equation of the giant atom-cavity-waveguide according to the equivalent Hamiltonian, is shown in the flowchart as Figure 5 shown and includes:

[0095] Step S0221, calculating the eigenstate in the single-exciton cavity-waveguide space according to the probability amplitude of the photons propagating right or left in the waveguide, the excitation amplitude of the cavity mode, and the excitation amplitude of the giant atom;

[0096] Step S0222, obtaining the system momentum equation of the giant atom-cavity-waveguide by solving the conventional Schrödinger equation.

[0097] In this embodiment, the eigenstate in the single-exciton cavity-waveguide space is expressed as:

[0098]

[0099] Among them, φ R (x) and φ L (x) represent the probability amplitudes of the photons propagating right or left in the waveguide, and u a (b) and u e are the excitation amplitudes of the cavity mode and the atom respectively.

[0100] According to the equivalent Hamiltonian of the waveguide QED system of the giant atom-cavity-waveguide, the photon frequency, and the eigenstate of the system, the Schrödinger equation is constructed and expressed as:

[0101]

[0102] where \(H\) represents the equivalent Hamiltonian of the system, and \(\omega\) represents the photon frequency.

[0103] The system momentum equation of the giant atom - cavity - waveguide is obtained by solving the conventional Schrödinger equation, which is expressed as:

[0104]

[0105] In an exemplary embodiment, in step S03, the transmittance expression of photons incident from the left is calculated according to the momentum equation, and the flowchart is as Figure 6 shown, including:

[0106] Step S031: Calculate the wave function expression of a single photon incident from the left end of the waveguide that satisfies the linear dispersion relation;

[0107] Step S032: When the photon reaches the coupling point of the cavity and the waveguide, the incident photon is transmitted or reflected according to the interaction between the waveguide and the cavity - giant atom;

[0108] Step S033: Calculate the transmittance expression of photons incident from the left according to the system momentum equation of the giant atom - cavity - waveguide.

[0109] In this embodiment, the scattering behavior of a single photon is studied. A single photon that satisfies the linear dispersion relation \(\omega = k\upsilon\) g is incident from the left end of the waveguide, and the wave functions \(\varphi\) R (x) and \(\varphi\) L (x) are expressed as:

[0110]

[0111] where the step function \(\theta(x)\) is expressed as:

[0112]

[0113] The photon is incident from the position \(x \lt 0\) on the left side of the waveguide and propagates freely in the waveguide. When it reaches the coupling point of the cavity and the waveguide (\(x = 0\)), due to the interaction between the waveguide and the cavity - atom, the incident photon may be reflected or transmitted. Solving for \(t\) L , it is expressed as:

[0114]

[0115] where:

[0116]

[0117] k j＝a,b,e = (\(\omega-\omega\) j +i\(\gamma\) j / 2);

[0118]

[0119] θ′ = θ b -θ a 。

[0120] In an exemplary embodiment, the step S04, calculating the transmittance expression of photons incident from the right according to the momentum equation, the flowchart is as Figure 7 shown, including:

[0121] Step S041, calculating the wave function expression of a single photon incident from the right end of the waveguide that satisfies the linear dispersion relation;

[0122] Step S042, when the photon reaches the cavity-waveguide coupling point, calculating the transmittance expression of the photon incident from the right according to the system momentum equation of the giant atom-cavity-waveguide.

[0123] In this embodiment, when considering the non-reciprocal scattering characteristics of the system, it is necessary to further consider injecting a single photon from the right side of the waveguide. At this time, the wave function is expressed as:

[0124]

[0125] wherein, the step function θ(x) is consistent with the left incidence.

[0126] The photon is incident from the position where x > 0 on the right side of the waveguide and propagates freely in the waveguide. When it reaches the point where the waveguide is coupled to the cavity (x = 0), due to the interaction between the waveguide and the cavity-atom, the incident photon may be reflected or transmitted, and solve for t R , expressed as:

[0127]

[0128] In an exemplary embodiment, the step S05, calculating the contrast function according to the transmittance of photons incident from different directions and modulating the system parameters of the giant atom-cavity-waveguide to achieve non-reciprocal photon routing, the flowchart is as Figure 8 shown, including:

[0129] Step S051, calculating the contrast function according to the transmittance of photons incident from the left and the transmittance of photons incident from the right;

[0130] Step S052, simplifying the contrast function according to the interactions between two cavities and the waveguide, the interactions between two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavity;

[0131] Step S053, modulating the interactions between two cavities and the waveguide, the interactions between two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavity to make the value of the simplified contrast function maximum;

[0132] Step S054: Adjust the system parameters to the interaction between the two cavities and the waveguide, the interaction between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameter of the cavity when the contrast value is maximized, so as to achieve non-reciprocal photon routing.

[0133] In this embodiment, the contrast is defined as T iso = T L - T R , where T R = |t R | 2 and T L = |t L | 2 . If T iso = 0, the system exhibits reciprocity, while when T iso = ±1, the system exhibits perfect non-reciprocity.

[0134] Calculate the contrast function T iso according to equations (13) and (15), which is expressed as:

[0135]

[0136] where Δ = ω - ω e = ω - ω a = ω - ω b , θ = kx0.

[0137] It can be seen from formula (16) that the value of the contrast T iso is related to parameters such as γ e , g a(b) , Γ a(b) , θ, etc., that is, the non-reciprocity is related to the dissipation of the atom, the dissipation of the cavity, the interaction between the atom and the cavity, the interaction between the cavity and the waveguide, the distance between the coupling points, etc.

[0138] To accurately analyze the influence of the interaction between the atom and the cavity, the interaction between the cavity and the waveguide, and the dissipation of the atom (cavity) on the non-reciprocity and reduce the calculation amount, simplify the contrast function according to the interaction between the two cavities and the waveguide, the interaction between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameter of the cavity, that is, let Γ a = Γ b = Γ, γ e = γ a = γ b = 2γ, g a = g b = g, and obtain the simplified contrast function, which is expressed as:

[0139]

[0140] where P = 2g2 γ - 3Δ 2 γ + γ 3 ;

[0141]

[0142] N = g 2 +γ 2 -Δ 2 +Γγ。

[0143] Modulate the interactions between the two cavities and the waveguide, the interactions between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavities according to the simplified contrast function.

[0144] Modulate the interactions between the two cavities and the waveguide, the interactions between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavities to maximize the value of the simplified contrast function. Through dynamic modulation, it is found that:

[0145] When γ = 2Γ, when g is large enough, at Δ = 0, T iso ≈ 1.

[0146] Further consider the influence of the coupling strength phase on the scattering characteristics and non - reciprocity. In different frequency bands, there are three peaks, and different coupling strength phases determine the sizes of the peaks. At Δ = 0, the peak reaches the maximum, T iso ≈ 1, almost achieving perfect non - reciprocity.

[0147] Consider the influence of the dissipation γ on the transmittance T L 、T R and the contrast T iso . When γ = 0, T iso is constantly equal to 0, and at this time, there is no non - reciprocity. When γ = Γ, the non - reciprocity is optimal at this time.

[0148] Consider the influence of the coupling strength g between the cavity and the atom on the transmittance T L 、T R and the contrast T iso . When other parameters remain unchanged, as the coupling strength g increases, the absolute value of the position of the peak points except Δ = 0 gradually increases, and the value of T iso gets closer and closer to 1.

[0149] According to the above dynamic modulation results, adjust the system parameters to the interactions between the two cavities and the waveguide, the interactions between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavities when the contrast is the largest (1 or as close to 1 as possible) to achieve non - reciprocal photon routing.

[0150] The non-reciprocity of photons plays an important role in the development of existing microwave magnetic isolators and optical quantum routing technologies at the single-photon level.

[0151] A computer-readable storage medium according to an embodiment of the present invention stores a computer program for electronic data exchange, wherein the computer program causes a computer to execute the above method.

[0152] An optical photon routing system based on a giant atom-cavity-waveguide according to an embodiment of the present invention has a structural schematic diagram as Figure 9 shown, including:

[0153] A waveguide QED system of a giant atom-cavity-waveguide;

[0154] A processor;

[0155] A memory;

[0156] And

[0157] One or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the programs cause a computer to execute the above method.

[0158] The method according to the present invention described above can be implemented in hardware, firmware, or be implemented as software or computer code that can be stored in a recording medium (such as a CD ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or be implemented as computer code that is originally stored in a remote recording medium or a non-transitory machine-readable medium and will be stored in a local recording medium and downloaded through a network, so that the method described herein can be stored on such software processing on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an ASIC or FPGA). It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component (such as RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the processing shown herein, the execution of the code converts the general-purpose computer into a dedicated computer for executing the processing shown herein.

[0159] Of course, those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present invention and are not intended as a limitation of the present invention. As long as it is within the scope of the present invention, changes and variations to the above embodiments will fall within the protection scope of the present invention.

Claims

1. A photon routing method based on giant atom-cavity-waveguide, characterized in that Including: Establishing a waveguide QED system model of a giant atom - cavity - waveguide; Calculating the system momentum equation of the giant atom - cavity - waveguide; Calculating the transmittance expression of photons incident from the left according to the momentum equation; Calculating the transmittance expression of photons incident from the right according to the momentum equation; Calculating the contrast function based on the transmittances of photons incident from different directions and modulating the system parameters of the giant atom - cavity - waveguide to achieve non - reciprocal photon routing.

2. The photon routing method based on giant atom-cavity-waveguide according to claim 1, wherein The waveguide QED system model of the giant atom - cavity - waveguide is a giant atom - cavity - waveguide structure in which two cavities are coupled to the same waveguide and a two - level giant atom is coupled to the two cavities.

3. The photon routing method based on giant atom-cavity-waveguide according to claim 2, wherein The calculating of the system momentum equation of the giant atom - cavity - waveguide includes the steps of: Calculating the equivalent Hamiltonian of the system using the real - space method; Calculating the system momentum equation of the giant atom - cavity - waveguide according to the equivalent Hamiltonian.

4. The photon routing method based on giant atom - cavity - waveguide according to claim 3, characterized in that, The calculating of the equivalent Hamiltonian of the system using the real - space method includes the steps of: Calculating the free Hamiltonian of the giant atom according to the resonant frequency and dissipation of the giant atom; Calculating the free Hamiltonian of the two cavities according to the resonant frequencies and dissipations of the two cavities, the creation operators and annihilation operators of the two cavities; Calculating the Hamiltonian of the waveguide according to the group velocity of photons propagating in the waveguide and the bosonic creation operator and bosonic annihilation operator of light; Calculating the Hamiltonian of the interaction between the waveguide and the cavities according to the interaction strength of the two cavities coupled to the waveguide; Calculating the Hamiltonian of the interaction between the giant atom and the cavities according to the coupling strength of the two - level giant atom coupled to the two cavities.

5. The method for photon routing based on giant atom-cavity-waveguide according to claim 3, characterized in that The calculating of the system momentum equation of the giant atom - cavity - waveguide according to the equivalent Hamiltonian includes the steps of: Calculating the eigenstates in the single - exciton cavity - waveguide space according to the probability amplitude of photons propagating right or left in the waveguide, the excitation amplitude of the cavity mode, and the excitation amplitude of the giant atom; Obtaining the system momentum equation of the giant atom - cavity - waveguide by solving the conventional Schrödinger equation.

6. The photon routing method based on giant atom-cavity-waveguide according to claim 1, wherein The calculating of the transmittance expression of photons incident from the left according to the momentum equation includes the steps of: Calculating the wave function expression of a single photon incident from the left end of the waveguide that satisfies the linear dispersion relation; When the photon reaches the cavity - waveguide coupling point, the incident photon is transmitted or reflected according to the interaction between the waveguide and the cavity - giant atom; Calculating the transmittance expression of photons incident from the left according to the system momentum equation of the giant atom - cavity - waveguide.

7. The photon routing method based on giant atom-cavity-waveguide according to claim 6, characterized in that, The calculating of the transmittance expression of photons incident from the right according to the momentum equation includes the steps of: Calculating the wave function expression of a single photon incident from the right end of the waveguide that satisfies the linear dispersion relation; Calculating the transmittance expression of photons incident from the right according to the system momentum equation of the giant atom - cavity - waveguide when the photon reaches the cavity - waveguide coupling point.

8. The method for photon routing based on giant atom-cavity-waveguide according to claim 7, wherein The calculating of the contrast function based on the transmittances of photons incident from different directions and modulating the system parameters of the giant atom - cavity - waveguide to achieve non - reciprocal photon routing includes the steps of: Calculating the contrast function according to the transmittance of photons incident from the left and the transmittance of photons incident from the right; Simplifying the contrast function according to the interaction between the two cavities and the waveguide, the interaction between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameters of the cavities. Adjust the interaction between the two cavities and the waveguide, the interaction between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameter of the cavity to maximize the value of the simplified contrast function; Adjust the system parameters to the interaction between the two cavities and the waveguide, the interaction between the two cavities and the giant atom, the dissipation of the giant atom, and the dissipation parameter of the cavity when the contrast value is maximized to achieve non-reciprocal photon routing.

9. A computer-readable storage medium storing a computer program for electronic data exchange, wherein, The computer program causes the computer to execute the method according to any one of claims 1-8.

10. A photon routing system based on giant atom-cavity-waveguide, characterized in that Comprising: A waveguide QED system of a giant atom-cavity-waveguide; A processor; A memory; And One or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the programs cause the computer to execute the method according to any one of claims 1-8.

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