High-speed data transmission method and device based on PT symmetric Rydberg cold atoms

Abstract

The invention provides a high-speed data transmission method and device based on PT symmetric Rydberg cold atoms, and relates to the technical field of optical information processing, and the method comprises the steps: constructing a four-layer atom system with an inverted Y structure; preparing Rydberg cold atoms based on the four-layer atom system with the inverted Y structure; the control light and the auxiliary light irradiate the Rydberg cold atoms, and PT symmetric non-harmonic potential is generated through modulation; vortex photoelasticity is generated in the Rydberg cold atoms with PT symmetric non-harmonic potential; and high-speed data transmission is realized based on stable propagation of vortex photoelasticity. According to the method provided by the invention, a four-layer atom system with an inverted Y structure is introduced, Rydberg cold atoms are prepared, a platform is designed for generating and controlling the vortex photoelastic to carry out stable propagation, the transmission speed of high-speed data is realized, and in addition, the application scene of PT symmetric optical non-harmonic potential is expanded.

Description

Technical Field

[0001] The present invention belongs to the field of optical information technology processing, and in particular relates to a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms. Background Art

[0002] Photoelasticity is a phenomenon in which isolated nonlinear waves confined in two spatial dimensions and dynamically evolving along the time axis achieve a complex balance between dispersion and diffraction through nonlinear mechanisms. Since the advent of nonlinear physics, the generation of photoelasticity has become a key area of ​​research, highlighting their important role in revolutionizing optical communication devices, achieving high-speed data operation capabilities, and advancing the frontiers of quantum information science. However, finding suitable media that can support the stable propagation of photoelasticity remains a challenge, which is mainly hindered by the collapse instability inherent in Kerr-type focusing media. To overcome this obstacle, researchers have proposed many new strategies, including spatially modulated nonlinear interactions, complex optical tandem configurations, and the use of materials with saturable, competing or nonlocal nonlinear responses, as well as the use of waveguide lattices. Recent research progress has achieved the stable propagation of photoelasticity in Rydberg cold atomic gases through the complex mechanism of electromagnetically induced transparency (EIT), thus providing a new promising route for stabilization.

[0003] Modulation of material parameters has been shown to be effective in achieving stable photoelasticity (LBs) by employing various techniques, including longitudinal tandem connections, graded-index fibers, and complex structures. Among these techniques, stable photoelasticity in transversely periodic media has attracted considerable attention, and its theoretical predictions have been experimentally confirmed in discrete waveguide arrays and continuous optical devices. Recently, new schemes using twisted waveguide arrays can support stable photoelasticity.

[0004] In all previous works, the transverse linear potential for stable 3D photoelasticity is real, i.e., it is mainly generated by the modulation of the refractive index. However, the discovery of fully real eigenvalues ​​in non-Hermitian Hamiltonians with parity-time (PT) symmetry has extended the possibilities of quantum theory to the complex domain. PT-symmetric photonic structures have become a promising way to achieve stable photoelasticity by suppressing the collapse of photoelasticity. Complex PT-symmetric periodic lattices with focused Kerr nonlinearity have been studied to explore the dynamic properties of elementary photoelasticity and vortex photoelasticity.

[0005] High-speed data transmission in quantum physics mainly relies on the unique advantages of quantum communication technology, which include higher security, transmission rate and transmission capacity. Through characteristics such as quantum superposition and quantum entanglement, multi-channel transmission can be achieved, thereby significantly improving the data transmission rate. Quantum bits (qubits) can exist in multiple states at the same time, which enables quantum communication to transmit more information at the same time. With the continuous development and maturity of quantum technology, high-speed data transmission in quantum physics is expected to be better developed and widely used in more fields.

[0006] Previous studies on the generation and propagation of photobolic particles have been predicted in azimuthal potential devices with PT symmetry, twisted circular waveguide arrays, and Rydberg atom devices. However, it is still unclear whether stable vortex photobolic particles (3D vortex LBs) can be achieved by combining Rydberg-Rydberg interaction (RRI) and PT-symmetric anharmonic lattice potentials.

[0007] Therefore, it is necessary to study the stable medium in the Rydberg cold atom device with rotational PT-symmetric anharmonic lattice potential, to illustrate that spatial distortion plays a key role in vortex photoelastic properties, and to explore high-speed data transmission methods in quantum physics. Summary of the invention

[0008] The purpose of the present invention is to address the problems existing in the prior art and to provide a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms. Not only by introducing a four-layer atomic configuration with an inverted Y structure and designing a platform for generating and controlling vortex photoelastics, but also discovering the unique degeneracy breaking phenomenon in vortex photoelastics with opposite topological charges, illustrating the key role of spatial distortion in the properties of vortex photoelastics in the manipulator, but also expanding the application scenarios of PT-symmetric optics and nonlinear dynamics.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows: Construct a four-layer atomic system with an inverted Y structure; Based on the four-layer atomic system with an inverted Y structure, Rydberg cold atoms are prepared; By irradiating the Rydberg cold atoms with control light and auxiliary light, the PT symmetric anharmonic potential is modulated. Generation of vortex photobombs in Rydberg cold atoms with PT-symmetric anharmonic potential; Based on the stable propagation of vortex light bombs, high-speed data transmission is achieved.

[0010] Furthermore, the preparation of Rydberg cold atoms comprises: Lowering the temperature of the atomic gas by laser cooling to bring the atomic gas close to absolute zero; After reaching a certain low temperature, the temperature of the atomic gas is further reduced by evaporative cooling; Laser or microwave pulses of a specific wavelength are used to excite the atomic gas to a highly excited Rydberg state, forming Rydberg cold atoms.

[0011] Furthermore, after the Rydberg cold atoms are prepared, the method further comprises placing the Rydberg cold atoms in a cylindrical (not limited to cylindrical) container: Choose the material and size of the container; Maintain a high vacuum inside the container; The temperature and magnetic field inside the container are precisely controlled.

[0012] Further, the modulation generates a PT symmetric anharmonic potential, comprising: Define the wave function that describes the amplitude of the detected light; The wave function expression is as follows:

[0013] in, , Represents external forces, is the horizontal coordinate, is the vertical coordinate, is the local interaction strength, VxDV It is the van der Waals force;

[0014] The wave function can be written in dimensionless form as follows:

[0015] in, , ,parameter ,in is the initial amplitude of the incident probe pulse; Rescaled potential Has the anharmonic form:

[0016]

[0017] in , and is a coefficient and The real and imaginary parts of the anharmonic potential; A PT symmetric potential is introduced, assuming that the Rydberg cold atomic system has a frequency Rotate, then the coordinates in the rotated image and There are the following relations:

[0018] The dimensionless form of the wave function can be written as the nonlinear Schrödinger equation as follows:

[0019] in, is the rotation operator.

[0020] Furthermore, the method of generating a vortex photoelasticity based on PT symmetric anharmonic potential and Rydberg cold atoms comprises: Based on the wave function, substituting the tentative solution of the vortex into the nonlinear Schrödinger equation to obtain the vortex solution; Based on the vortex solution, adjusting the real eigenvalue and the imaginary eigenvalue of the anharmonic potential; Based on the real and imaginary eigenvalues ​​of the anharmonic potential, combined with the PT symmetric anharmonic potential and Rydberg cold atoms, vortex photoelastics with topological charge are generated.

[0021] Further, the adjusting the real part eigenvalue and the imaginary part eigenvalue of the anharmonic potential comprises: In the linear case, the real part of the eigenvalue , with the rotation frequency Varies with the changes of: when When , the vortex photoelastic state with opposite topological charges is degenerate, for example ; when When The real part of the vortex light bullet No longer degenerate; Under the PT symmetry condition, the real part eigenvalue of the anharmonic potential is a positive real value , while the imaginary eigenvalue is zero.

[0022] Furthermore, when the topological charge of the vortex photoelastic is positive, the phase structure rotates counterclockwise, and when the topological charge is negative, the phase structure rotates clockwise.

[0023] A high-speed data transmission device based on PT symmetric Rydberg cold atoms, characterized by comprising: The inverted Y-structured four-layer atomic system is used for transitions between atoms at different levels and to create the necessary conditions for the generation of Rydberg cold atoms; cooling devices, used to reduce the temperature of atoms to near absolute zero; Laser pulse device, used to excite atoms close to absolute zero into Rydberg state, generating Rydberg cold atoms; Non-conductive containers for holding Rydberg cold atoms; Light source module, used to modulate the generation of PT-symmetric anharmonic potential in Rydberg cold atoms; The vortex photoelasticity generation module is used to generate vortex photoelasticity in Rydberg cold atoms with PT symmetric anharmonic potential to achieve high-speed data transmission.

[0024] Furthermore, the temperature and magnetic field of the non-conductive container are controlled to eliminate the influence of thermal noise and magnetic field noise on the Rydberg cold atoms.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention proposes a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms, which prepares Rydberg cold atoms by introducing a four-layer atomic system with an inverted Y structure and designs a platform for generating and controlling topologically charged atoms. Vortex light bomb; 2. The present invention proposes a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms, which modulates and generates PT-symmetric anharmonic potential by controlling light and auxiliary light irradiation, and dynamically modulates by propagation constant and non-local nonlinearity, highlighting the key role of PT-symmetric anharmonic potential in vortex photoelastic properties; 3. The present invention proposes a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms, which not only improves the speed of high-speed data transmission, but also expands the application scenarios of PT-symmetric optics and anharmonic potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic flow chart of a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms provided in an embodiment of the present invention; Figure 2 A schematic diagram of a rotating Rydberg atomic system based on a high-speed data transmission method and device of PT-symmetric Rydberg cold atoms provided in an embodiment of the present invention; Figure 3 Intensity distribution diagram of vortex photoelastics with different rotation frequencies and topological charges in a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms provided in an embodiment of the present invention; Figure 4 A diagram showing parameter changes of a photoelastic device under rotation and non-rotation for a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms provided by an embodiment of the present invention; Figure 5 A relationship diagram between the photoelastic power, propagation constant and linear stability of a high-speed data transmission method and device based on PT-symmetric Rydberg cold atoms provided in an embodiment of the present invention; Figure 6 A diagram showing the propagation of a vortex optical bomb based on a high-speed data transmission method and device of PT-symmetric Rydberg cold atoms provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1 As shown, an embodiment of the present invention provides a flow chart of a high-speed data transmission method based on PT-symmetric Rydberg cold atoms, including: constructing a four-layer atomic system with an inverted Y structure; preparing Rydberg cold atoms based on the four-layer atomic system with an inverted Y structure; modulating and generating PT-symmetric anharmonic potential by irradiating the Rydberg cold atoms with controlled light and auxiliary light; generating vortex light bombs in the Rydberg cold atoms with PT-symmetric anharmonic potential; and realizing high-speed data transmission based on the stable propagation of the vortex light bombs.

[0030] Specifically, the preparation of Rydberg cold atoms comprises: Lowering the temperature of the atomic gas by laser cooling to bring the atomic gas close to absolute zero; After reaching a certain low temperature, the temperature of the atomic gas is further reduced by evaporative cooling; Laser or microwave pulses of a specific wavelength are used to excite the atomic gas to a highly excited Rydberg state, forming Rydberg cold atoms.

[0031] Specifically, after the Rydberg cold atoms are prepared, the method further comprises placing the Rydberg cold atoms in a cylindrical (not limited to cylindrical) container: Choose the material and size of the container; Maintain a high vacuum inside the container; The temperature and magnetic field inside the container are precisely controlled.

[0032] Specifically, the modulation generates a PT symmetric anharmonic potential, including: Define the wave function that describes the amplitude of the detected light; The wave function expression is as follows:

[0033] in, , Represents external forces, is the horizontal coordinate, is the vertical coordinate, is the local interaction strength, VxDV It is the van der Waals force;

[0034] The wave function can be written in dimensionless form as follows:

[0035] in, , ,parameter ,in is the initial amplitude of the incident probe pulse; Rescaled potential Has the anharmonic form:

[0036]

[0037] in , and is a coefficient and The real and imaginary parts of the anharmonic potential;

[0038] A PT symmetric potential is introduced, assuming that the Rydberg cold atomic system has a frequency Rotate, then the coordinates in the rotated image and There are the following relations:

[0039] The dimensionless form of the wave function can be written as the nonlinear Schrödinger equation as follows:

[0040] in, is the rotation operator.

[0041] Specifically, the method of generating a vortex photoelastic bomb based on PT symmetric anharmonic potential and Rydberg cold atoms includes: Based on the wave function, substituting the tentative solution of the vortex into the nonlinear Schrödinger equation to obtain the vortex solution; Based on the vortex solution, adjusting the real eigenvalue and the imaginary eigenvalue of the anharmonic potential; Based on the real and imaginary eigenvalues ​​of the anharmonic potential, combined with the PT symmetric anharmonic potential and Rydberg cold atoms, vortex photoelastics with topological charge are generated.

[0042] Specifically, the adjusting the real part eigenvalue and the imaginary part eigenvalue of the anharmonic potential includes: In the linear case, the real part of the eigenvalue , with the rotation frequency Varies with the changes of: when When , the vortex photoelastic state with opposite topological charges is degenerate, for example ; when When The real part of the vortex light bullet No longer degenerate; Under the PT symmetry condition, the real part eigenvalue of the anharmonic potential is a positive real value , while the imaginary eigenvalue is zero.

[0043] Specifically, when the topological charge of the vortex photoelastic bomb is positive, the phase structure rotates counterclockwise, and when the topological charge is negative, the phase structure rotates clockwise.

[0044] The embodiment of the present invention also provides a device for generating and manipulating vortex light in a Rydberg cold atom system based on PT symmetric anharmonic potential: 1. Generation of Rydberg cold atoms based on laser cooling and evaporative cooling To prepare Rydberg cold atomic gas, it is first necessary to lower the temperature of the atomic gas to close to absolute zero.

[0045] Laser cooling can control the interaction between laser and atoms by adjusting laser parameters (such as laser power, pulse width, repetition frequency, wavelength and polarization, etc.), thereby effectively reducing the thermal motion speed of atoms and achieving cooling. Specifically, the basic principle of laser cooling is to use the light pressure effect of laser beam on matter: when the laser beam is irradiated on atoms, photons will interact with atoms, thereby changing the momentum of atoms and generating light pressure. Due to the Doppler effect, the wavelength felt by atoms moving toward the laser will appear shorter, so the effect is strong; while the wavelength felt by atoms moving away from the laser will be longer, so the effect is very weak; in this way, if there is a laser beam in six directions: front, back, left, right, up and down, the speed of atoms can be reduced to achieve cooling.

[0046] After reaching a certain low temperature, the temperature needs to be further lowered through technologies such as evaporative cooling. Through evaporative cooling, the temperature of the atomic gas can be lowered to a level close to absolute zero, and then a laser or microwave pulse of a specific wavelength is used to excite some of the ground state atoms to a highly excited Rydberg state, forming Rydberg cold atoms.

[0047] 2. Place the Rydberg cold atoms in a cylindrical (not limited to cylindrical) container First, choose the material and size of the container. The material of the container should be non-conductive or insulating to avoid unnecessary electromagnetic interference to the Rydberg atoms. The size of the container should be large enough to avoid the influence of boundary effects on the Rydberg atoms. Secondly, a high vacuum should be maintained inside the container to reduce collisions between other gas molecules or atoms and the Rydberg atoms, which helps maintain the stability and lifespan of the Rydberg atoms. Finally, precise control of the temperature and magnetic field inside the container according to actual needs helps eliminate the effects of thermal noise and magnetic field noise on the Rydberg atoms.

[0048] 3. Modulation of PT symmetric anharmonic potential in Rydberg cold atomic gas by controlling light and auxiliary light irradiation In the four-level atomic energy level structure, an atom has a ground state, an intermediate excited state and a highly excited Rydberg state. Control light and auxiliary light are usually used to couple these energy levels to achieve the transition of atoms between different energy levels. Control light and auxiliary light are used to couple the ground state to the intermediate excited state and the intermediate excited state to the Rydberg state, respectively.

[0049] By adjusting the frequency, phase, polarization, intensity, etc. of the control light and the auxiliary light, an interference pattern with PT symmetry can be formed in space. The laser beam is generated using tools such as an axicon lens or a spatial light modulator. The non-diffraction characteristics of the laser beam enable it to maintain a certain light intensity distribution and phase structure during propagation. The laser beam interacts with the Rydberg cold atomic gas and modulates the PT symmetric anharmonic potential through nonlinear optical effects, such as Figure 2 shown.

[0050] 4. Experimental parameters Will Cold atomic gas is used as the experimental object. It is assumed that the laser field propagates in the material, where the wavelength , refractive index , ,as well as , then the diffraction length .

[0051] Typical parameters for Rydberg atoms and coupled fields are: , , , , , , , , ,and , the radius of the soft core is estimated to be , .

[0052] The embodiment of the present invention also provides the principle of a device for generating and manipulating vortex light in a Rydberg cold atom system based on PT symmetric anharmonic potential: 1. By adjusting the laser parameters and controlling the interaction between the laser and atoms, and further reducing the temperature through technologies such as evaporative cooling, the preparation of Rydberg cold atomic gas can be achieved.

[0053] 2. Through incentives Entering the Rydberg excited state, the four-level structure presents a ladder structure. The electrons in this excited state have a long lifetime and a large orbital radius, which makes the Rydberg atom show unique advantages in the fields of optical information processing and optical simulation. In particular, the strong interaction between Rydberg atoms provides rich physical resources for the processing of optical information.

[0054] 3. By controlling the light and auxiliary light irradiated in the Rydberg atomic gas, the PT-symmetric anharmonic potential is modulated. The PT-symmetric anharmonic potential system has some unique properties, such as non-Hermitian Hamiltonian, real eigenvalues, etc., which provide new perspectives and tools for the propagation and manipulation of light, and provide a rich physical environment for the propagation and manipulation of light. The PT-symmetric anharmonic potential can realize multi-channel transmission through the characteristics of quantum superposition and quantum entanglement, thereby significantly improving the data transmission rate, that is, having a higher transmission rate and transmission capacity during the data transmission process.

[0055] The embodiment of the present invention also provides a specific implementation of a device for generating and manipulating vortex light in a Rydberg cold atom system based on PT symmetric anharmonic potential: 1. Rydberg cold atom energy level The present invention proposes a four-level atomic system with an inverted Y-type configuration, the system is composed of a Rydberg cold atomic medium, and the four-level structure is as follows Figure 2 (a), where four levels are considered, namely , , and a highly excited Rydberg state A detection field (angular frequency is , the Rabi frequency is ) is coupled and A control field (angular frequency is , the Rabi frequency is ) is coupled and and an auxiliary field (with an angular frequency of , the Rabi frequency is ) is coupled and highly excited Rydberg states The coupling detuning of the detection field, control field and auxiliary light field is and .according to Figure 1 (b) Yes ,in, It is various The angular frequency, It is from the state Arrival The probability of spontaneous transition is is the pumping rate of the incoherent pumping, used to move atoms from Pump to , thus providing gain to the system.

[0056] The present invention studies a four-level inverted Y-type atomic system modified by Rydberg states, such as Figure 2 (a). Each atom contains four energy levels, which are marked as , , and , a weak probe light (frequency , the half-Rabi frequency is ) Coupling Level and , and a control light (frequency is , the half-Rabi frequency is ) Coupling Level and In addition, an auxiliary beam (frequency , the half-Rabi frequency is ) and from the energy level Transition to the Rydberg state The atomic interactions of Rydberg electromagnetically induced transparent systems are established, such as Figure 2 (b) as shown. Indicates energy level and The spontaneous emission rate between represents the single-photon detuning, and and represents the two-photon detuning, where It is related to the atomic energy level The system uses a coupled pump The energy level in the system Towards The transition provides gain.

[0057] 2. Realization of optical anharmonic potential with PT symmetry Under the conditions of paraxial and slowly varying envelope approximation, the wave function expression describing the amplitude of the probe light is as follows: (1) in, , It is external force. Represents time, , Represent the horizontal and vertical coordinates respectively. is the local interaction strength, representing a measure of the cubic Kerr nonlinearity of the medium.

[0059] The long-range Rydberg interaction in formula (1) has van der Waals force, which is expressed as follows: (2) in, is Planck's constant, is the dispersion parameter, is the position of the Rydberg atom, is the Rydberg soft core radius. and , the vertical coordinate is Normalized, where is the diffraction length, is the wave number, and by scaling, the local nonlinear coefficient is set to .

[0060] Formula (1) is written in dimensionless form as follows: (3) in, , dimensionless nonlocal parameter , is the initial amplitude of the incident probe pulse, and the degree of nonlocality is determined by the parameter Decide.

[0061] By adjusting and For values ​​of , the nonlinear system exhibits three types of local regions: , generally non-local area , and strong non-local regions .

[0062] Rescaled potential has an anharmonic form, as follows:

[0063] (4) in, , and is a coefficient and The real and imaginary parts of the anharmonic potential, and The spatial distribution of Figure 2(c) and (d). Therefore, the complex potential Satisfaction relationship , we introduce a PT-symmetric potential and then obtain the completely real spectrum from the non-Hermitian system.

[0064] Assume that the Rydberg cold atom system has a frequency Rotate, then the coordinates in the rotated image and There are the following relations: (5)

[0065] Formula (3) can be written as: (6) in, is the rotation operator. For simplicity, The apostrophe in is omitted.

[0066] In this step, Cold atomic gas is used as the experimental object. Assume that the laser field propagates in the material, where the wavelength , refractive index , ,as well as , then the diffraction length is estimated to be .

[0067] Typical parameters for Rydberg atoms and coupled fields are: , , , , , , , , ,and , the radius of the soft core is estimated to be This system mainly works in general non-local areas, so .

[0068] 3. Generation of vortex photoelastics in a Rydberg cold atomic system with PT-symmetric anharmonic potential The tentative solution assuming vortex localization is: (7) in, is the propagation distance The independent steady-state solutions, is an integer topological charge, is the azimuth, is the propagation constant. Substituting into equation (6) to obtain the vortex solution, the generated topological charge ( )'s vortex light bomb.

[0069] A weak perturbation form is introduced in the trial solution, and the expression is: (8) in, and is a small disturbance, ,symbol represents the complex conjugate, Usually a complex eigenvalue representing the unstable growth rate of the perturbation.

[0070] Will Substituting into equation (6) and linearizing it near the steady-state solution, we can obtain the eigenvalue ,when , the vortex light bomb can propagate stably.

[0071] The profile of the vortex light bomb in the embodiment of the present invention is as follows: Figure 3 As shown in the figure, the vortex light bomb is Intensity distribution and phase structure on the plane. With the topological charge As the frequency increases from 1 to 2, the profile of the vortex photobomb changes from the standard ring mode to the quad-core vortex mode, and the positive and negative topological charges cause counterclockwise and clockwise phase rotations, respectively. With the increase of In the case of , a slight decrease in the localization of the vortex photobomb was observed.

[0072] When the Kerr local nonlinearity and the Rydberg-induced nonlocal nonlinearity equation (6) are removed, the equation is transformed into a linear equation with infinite eigenvalues ​​and corresponding linear eigenmodes. The characteristics of the nonlinear mode can be partially understood in terms of the linear mode, because the nonlinear mode can be transformed from the linear mode when the local and nonlocal nonlinearities cannot be ignored. In the linear case, the dispersion relation is Figure 4 (a), where the real part of the eigenvalue With the rotation frequency Varies with the changes of: when When , it is found that the vortex photoelastic state with opposite topological charges is degenerate, e.g. ; when When The real part of the vortex light bullet No longer simplified.

[0073] Under the PT symmetry condition, the nonlinear system can fully exhibit positive real-valued eigenvalues , while the imaginary eigenvalue is zero, which indicates that the system has entered a PT symmetric cycle phase: In order to stabilize this solution, we can adjust the actual eigenvalue and the imaginary eigenvalue To achieve this, Figure 4 The situation shown in (b) is similar. Figure 4 In (b), the lower area represents the PT symmetric phase, while the upper area corresponds to the shaded area, which indicates that the system has lost PT symmetry and entered the PT symmetry-breaking phase.

[0074] At fixed parameters and In this case, the PT symmetry of the system can be adjusted by adjusting this anharmonic potential The imaginary part is used to manipulate Figure 4 (c) and (d) are respectively and This is explained as an example: In no rotation In the case of , the real eigenvalues ​​of the vortex photoelastics with opposite topological charge signs (e.g., ) are equal, which shows that for and The degeneracy of the vortex photoelasticity, such as Figure 4 (c) is shown. Similarly, this phenomenon also applies to and Vortex light bomb.

[0075] There is also a threshold point (marked as point ),at this time , when it is less than this threshold, the system exhibits PT symmetry, and all eigenvalues ​​are real numbers, that is, ; However, when When The curve forks into two different branches, indicating , in this case, no stable solution can be obtained.

[0076] Under rotating conditions Figure 4 (d) The real and imaginary parts of The relationship between is similar to that in the non-rotation condition, but there are two differences: First, the critical point The bifurcation occurs earlier, specifically at the critical point Department,

[0077] This shows that the introduction of rotation makes the PT symmetry condition more stringent; secondly, the vortex photoelastic with opposite topological charge signs at point This result shows that the addition of rotation leads to the breaking of the internal degeneracy of the system, thus showing a richer spectrum of soliton configurations through angular momentum.

[0078] Figure 5 Demonstrated the vortex light bomb Relationship, under the control of system parameters, the topological charge is and The vortex photoelasticity does not show degeneracy, which is due to Figure 5 Points in (a) and In contrast, for the topological charge and There are two different response areas for the vortex light bomb:

[0079] when When the topological charge is and The states of the vortex photobombs become degenerate, making them indistinguishable (in Figure 5 (a) Use point and express); when When , the degeneracy is broken and the two vortex photobullets become distinguishable, such as Figure 5 Points in (a) and shown.

[0080] exist Figure 5 In (a), the solid line and the dashed line represent the stable and unstable vortex light bombs, respectively. , and Under this condition, for the topological charge The stability domain of the vortex photoelastic The ranges are [9.8~15.4], [10~14.82], [6~10] and [6.8~10.4] respectively. These stability domains are Figure 5 The linear stability analysis in When stable, in numerical calculations, the accuracy is Therefore, the vortex light bombs found in the present invention are not completely stable, and they will gradually become unstable during the propagation process.

[0081] Figure 6 It shows that in the stable domain, the rotation frequency The propagation of the vortex photobomb is compared with the topological charge By comparison, The propagation of vortex light bullets is more robust and can reach a distance of , in physical units it is approximately ; Although there are fuzzy points at the phase edge during propagation, the internal phase structure of these vortex light bullets remains consistent, and their intensity distribution also maintains remarkable stability; when , they can shorten the distance over which they can travel without significant distortion, specifically, The vortex light bomb can stably propagate to ,and The vortex light bomb can only stably propagate to (corresponding to 0.36m).

[0082] The embodiment of the present invention further provides a high-speed data transmission device based on PT symmetric Rydberg cold atoms, comprising the following process: The inverted Y-structured four-layer atomic system is used for transitions between atoms at different levels and to create the necessary conditions for the generation of Rydberg cold atoms. A cooling device is used to reduce the temperature of the atoms to near absolute zero. The generated Rydberg cold atoms are then placed in a non-conductive container, and the temperature and magnetic field inside the container are controlled to eliminate the effects of thermal noise and magnetic field noise on the Rydberg atoms. The energy levels in the inverted Y-structured four-layer atomic system are coupled through a light source module, and a laser beam is generated using an axicon lens or a spatial light modulator. The laser beam interacts with the Rydberg cold atoms, and a PT-symmetric anharmonic potential is modulated through nonlinear optical effects. Finally, a vortex light bomb is generated in the Rydberg cold atoms with the PT-symmetric anharmonic potential to ensure stable propagation and achieve high-speed data transmission.

[0083] Finally, it should be pointed out that the above specific embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above specific embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above specific embodiments based on the technical essence of the present invention should be considered to belong to the protection scope of the present invention.

Claims

1. A high-speed data transmission method based on PT symmetric Rydberg cold atoms, characterized in that: The following steps are involved: Construct a four-layer atomic system with an inverted Y structure; Based on the four-layer atomic system with an inverted Y structure, Rydberg cold atoms are prepared; By irradiating the Rydberg cold atoms with control light and auxiliary light, the PT symmetric anharmonic potential is modulated. Generation of vortex photobombs in Rydberg cold atoms with PT-symmetric anharmonic potential; Based on the stable propagation of vortex light bombs, high-speed data transmission is achieved.

2. The high-speed data transmission method based on PT symmetric Rydberg cold atoms according to claim 1, characterized in that: The method for preparing Rydberg cold atoms comprises: Lowering the temperature of the atomic gas by laser cooling to bring the atomic gas close to absolute zero; After reaching a preset low temperature, further reducing the temperature of the atomic gas by evaporative cooling; Laser or microwave pulses of a specific wavelength are used to excite the atomic gas to a highly excited Rydberg state, forming Rydberg cold atoms.

3. The high-speed data transmission method based on PT symmetric Rydberg cold atoms according to claim 1, characterized in that: After the Rydberg cold atoms are prepared, the method further comprises placing the Rydberg cold atoms in a container: Choose the material and size of the container; Maintain a high vacuum inside the container; The temperature and magnetic field inside the container are precisely controlled.

4. The high-speed data transmission method based on PT symmetric Rydberg cold atoms according to claim 1, characterized in that: The modulation generates a PT symmetric anharmonic potential, including: Define the wave function that describes the amplitude of the detected light; The wave function expression is as follows: in, , Represents external forces, is the horizontal coordinate, is the vertical coordinate, is the local interaction strength, Vvdw is the van der Waals force; The wave function can be written in dimensionless form as follows: in, , ,parameter ,in is the initial amplitude of the incident probe pulse; Rescaled potential Has the anharmonic form: in , and is a coefficient and The real and imaginary parts of the anharmonic potential; A PT symmetric potential is introduced, assuming that the Rydberg cold atomic system has a frequency Rotate, then the coordinates in the rotated image and There are the following relations: The dimensionless form of the wave function can be written as the nonlinear Schrödinger equation as follows: in, is the rotation operator.

5. The high-speed data transmission method based on PT symmetric Rydberg cold atoms according to claim 4, characterized in that: The method of generating a vortex photoelastic bomb based on PT symmetric anharmonic potential and Rydberg cold atoms includes: Based on the wave function, substituting the tentative solution of the vortex into the nonlinear Schrödinger equation to obtain the vortex solution; Based on the vortex solution, adjusting the real eigenvalue and the imaginary eigenvalue of the anharmonic potential; Based on the real and imaginary eigenvalues ​​of the anharmonic potential, combined with the PT symmetric anharmonic potential and Rydberg cold atoms, vortex photoelastics with topological charge are generated.

6. The high-speed data transmission method based on PT symmetric Rydberg cold atoms according to claim 5, characterized in that: The step of adjusting the real eigenvalue and the imaginary eigenvalue of the anharmonic potential comprises: In the linear case, the real part of the eigenvalue , with the rotation frequency Varies with the changes of: when When , the vortex photoelastic state with opposite topological charges is degenerate, for example ; when When The real part of the vortex light bullet No longer degenerate; Under the PT symmetry condition, the real part eigenvalue of the anharmonic potential is a positive real value , while the imaginary eigenvalue is zero.

7. The high-speed data transmission method based on PT symmetric Rydberg cold atoms according to claim 5, characterized in that: When the topological charge of the vortex photoelastic is positive, the phase structure rotates counterclockwise, and when the topological charge is negative, the phase structure rotates clockwise.

8. The high-speed data transmission device based on PT symmetric Rydberg cold atoms according to claim 1, characterized in that: include: The inverted Y-structured four-layer atomic system is used for transitions between atoms at different levels and to create the necessary conditions for the generation of Rydberg cold atoms; cooling devices, used to reduce the temperature of atoms to near absolute zero; Laser pulse device, used to excite atoms close to absolute zero into Rydberg state, forming Rydberg cold atoms; Non-conductive containers for holding Rydberg cold atoms; Light source module, used to modulate the generation of PT-symmetric anharmonic potential in Rydberg cold atoms; The vortex photoelasticity generation module is used to generate vortex photoelasticity in Rydberg cold atoms with PT symmetric anharmonic potential to achieve high-speed data transmission.

9. The high-speed data transmission device based on PT symmetric Rydberg cold atoms according to claim 8, characterized in that: The non-conductive container is characterized in that The temperature and magnetic field of the non-conductive container are controlled to eliminate the influence of thermal noise and magnetic field noise on Rydberg cold atoms.

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