A high-dimensional encoded quantum random number generator and a method for generating quantum random numbers.

Abstract

This application discloses a high-dimensional encoded quantum random number generator and a method for generating quantum random numbers. The high-dimensional encoded quantum random number generator includes an entangled photon source, a wavelength splitter, at least one photon encoding and detection module, and a data processing module. The photon encoding and detection module includes a first filter, a second filter, a dispersive device, a beam splitting module, a first photon detector, a second photon detector, and a third photon detector. This application uses multiple photon processing through the dispersive device and the beam splitting module to perform high-dimensional time encoding on a single photon. Under the condition of entangled photon pairs at the same rate, a single photon can be converted into a quantum random number with a higher number of bits, thereby improving the random number generation rate.

Description

Technical Field

[0001] This application belongs to the field of quantum communication technology, specifically, it relates to a quantum random number generator and a method for generating quantum random numbers. Background Technology

[0002] Random numbers are a crucial resource in cryptography. Both classical and quantum cryptography impose stringent requirements on the randomness of random numbers, which directly determines the security of most cryptographic systems. Furthermore, random numbers have wide applications outside of cryptography, playing a vital role in activities, sampling statistics, Monte Carlo simulations, and various aspects of computational science. A quantum random number generator (QRNG) is a device that generates random numbers using quantum mechanical effects. The random numbers it produces not only possess inherent randomness and security, but also, due to improvements in the bandwidth of the entropy source, the detection bandwidth of the processing circuit, and its efficiency, have led to its widespread application in numerous fields.

[0003] In the field of quantum random number generators, schemes based on single-photon sources that generate quantum random numbers by measuring the path quantum state or time quantum state of photons are commonly used in practical quantum random number generators. However, these techniques are generally limited to low-power operation because excessive power can generate multiphoton states. Multiphoton phenomena introduce classical correlations or classical noise, leading to a decrease in the entropy source quality of random numbers. While low-power operation can mitigate or avoid multiphoton phenomena, it results in a lower quantum random number generation rate. Summary of the Invention

[0004] To address the problem of low random number generation rate in practical quantum random number generators based on single-photon sources, this application provides a high-dimensional encoded quantum random number generator, the specific scheme of which is as follows.

[0005] This application discloses a high-dimensional encoded quantum random number generator, including an entangled photon source, a wavelength splitter, at least one photon encoding and detection module, and a data processing module; the entangled photon source is used to generate at least one entangled photon pair with wavelength combination (λa&λb), and the wavelength splitter is connected to the entangled photon source to separate the two photons in the entangled photon pair and output them from the first photon end and the second photon end, respectively.

[0006] The photon encoding and detection module includes a first filter, a second filter, a dispersive device, a beam splitter module, a first photon detector, a second photon detector, and a third photon detector. The first and second filters are used to filter the light output from the first and second photon ends. The photons passing through the second filter are directly output to the third photon detector. The dispersive device is connected to the first filter and is used to time-spread the passing photons to m time intervals, corresponding to m time patterns, where m is a positive integer.

[0007] The beam splitting module is connected to the output of the dispersive device and is used to perform high-dimensional time encoding on the passing photons. The beam splitting module includes n beam splitters connected in series, where n is a positive integer. Each beam splitter includes an upper input, a lower input, an upper output, and a lower output. The upper output of the i-th beam splitter is connected to the upper input of the (i+1)-th beam splitter by an i-th delay unit, or the lower output of the i-th beam splitter is connected to the lower input of the (i+1)-th beam splitter by an i-th delay unit, where i is an integer from 1 to n-1.

[0008] The photons entering the beam-splitting module are ultimately output from either the upper output of the nth beam splitter to the first photon detector or from the lower output of the nth beam splitter to the second photon detector. Depending on the different paths the photons take, the beam-splitting module broadens the photons to 2... n In each time period, photons are encoded into a total of m*2 n A time pattern.

[0009] The data processing module connects to the photon encoding and detection module. It calculates the times when the first and second photon detectors detected the photon, using the time of detection by the third photon detector as zero, and converts this time into a bit count of log2(m*2). n Quantum random numbers.

[0010] Optionally, the entangled photon source includes a laser and a nonlinear medium connected in sequence, wherein the nonlinear medium is one of silicon-based waveguide, silicon nanowire, silicon microring resonator, or periodically polarized lithium niobate waveguide.

[0011] Optionally, the wavelength splitter can be an on-chip MZ interferometer or an on-chip multimode interferometer.

[0012] Optionally, the first filter and the second filter are on-chip micro-ring resonators.

[0013] Optionally, the dispersive device is a dispersive waveguide or a dispersive grating.

[0014] Preferably, the optical delay of the photon by the first delay unit is Δt, and the optical delay of the photon by the i-th delay unit is 2. i-1 *Δt.

[0015] Furthermore, the high-dimensional encoded quantum random number generator includes multiple photon encoding and detection modules; the wavelength splitter is a dense wavelength division multiplexer; the entangled photon source is used to provide entangled photon pairs with various wavelength combinations (λ1a&λ1b, λ2a&λ2b, ..., λna&λnb); each photon encoding and detection module processes one type of entangled photon pair with wavelength combination (λia&λib); the data processing module processes the detection results of each photon encoding and detection module, finally obtaining n sets of bits with a number of log2(m*2). n Quantum random numbers.

[0016] This application also provides a quantum random number generation method, applied to the above-mentioned high-dimensional encoded quantum random number generator, the method comprising:

[0017] An entangled photon source generates at least one entangled photon pair with a wavelength combination (λa & λb);

[0018] The wavelength splitter separates the two photons in an entangled photon pair and outputs them from the first photon end and the second photon end, respectively;

[0019] The first filter and the second filter filter the light output from the first photon end and the second photon end, respectively.

[0020] Photons passing through the second filter are directly output to the third photon detector for photon detection;

[0021] Photons passing through the first filter enter the dispersive device, which time-widens the photons to m time intervals, corresponding to m time patterns, where m is a positive integer.

[0022] The beam-splitting module further encodes the photons output from the dispersive device in high dimensions, and outputs the photons either from the upper output of the nth beam splitter to the first photon detector or from the lower output of the nth beam splitter to the second photon detector. Depending on the different paths the photons take, the beam-splitting module broadens the photons to 2... n In each time period, photons are encoded into a total of m*2 n A time pattern;

[0023] The data processing module calculates the detection times of the first and second photon detectors, using the time when the third photon detector detects the photon as the zero point, and converts it into a bit count of log2(m*2). n Quantum random numbers.

[0024] Furthermore, this high-dimensional encoded quantum random number generator includes multiple photon encoding and detection modules, a dense wavelength division multiplexer (DWDM) for the wavelength splitter, and an entangled photon source to provide entangled photon pairs with various wavelength combinations. Each photon encoding and detection module processes one type of entangled photon pair with a specific wavelength combination. The data processing module processes the detection results from each photon encoding and detection module, ultimately obtaining n sets of bits with a total number of log2(m*2). n Quantum random numbers.

[0025] Furthermore, the data processing module selects at least two of the n sets of quantum random numbers, performs XOR processing on them, and outputs the results.

[0026] In summary, compared with the prior art, the above-described technical solutions conceived in this application can achieve the following beneficial effects:

[0027] This application provides a high-dimensional encoded quantum random number generator. It employs multi-photon processing via a dispersive device and a beam splitter module to perform high-dimensional time encoding on single photons. Under the same entangled photon pairs at the same rate, a single photon can be converted into a quantum random number with a higher number of qubits, thereby improving the random number generation rate. Furthermore, this technical solution can operate at the standard power of existing practical quantum random number generators, avoiding the occurrence of multi-photon phenomena. It eliminates the need for photon-resolved detectors and can more fully utilize the temporal resolution of existing single-photon detectors without incurring additional costs. It boasts strong practicality and scalability, and can significantly increase the quantum random number output rate of practical quantum random number generators. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A schematic diagram of a high-dimensional encoded quantum random number generator provided in this application embodiment;

[0030] Figure 2 This is a schematic diagram of the wavelength splitter in the embodiments of this application;

[0031] Figure 3 This is a schematic diagram of the on-chip microring resonator in the embodiments of this application;

[0032] Figure 4 This is a schematic diagram of the effect of a dispersive device on photons of different frequencies;

[0033] Figure 5 This is a schematic diagram of the effect of the dispersive device on a single photon in an embodiment of this application;

[0034] Figure 6 This is a schematic diagram showing different paths of photons in the beam splitting module in the embodiments of this application;

[0035] Figure 7 This is a schematic diagram illustrating the time pattern of photons after traversing different paths in the embodiments of this application;

[0036] Figure 8 A schematic diagram of yet another high-dimensional encoded quantum random number generator provided in this application;

[0037] Figure 9 A schematic diagram showing the interaction of multiple dispersive devices in multiple photon encoding and detection modules with photons of different frequencies;

[0038] Figure 10 This is a schematic diagram illustrating the interaction of multiple dispersive devices of multiple photon encoding and detection modules on a single photon in an embodiment of this application;

[0039] Figure 11 A flowchart of a quantum random number generation method provided in an embodiment of this application. Detailed Implementation

[0040] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0042] To address the problem of low random number generation rate in practical quantum random number generators based on single-photon sources, this application provides a high-dimensional encoded quantum random number generator and a quantum random number generation method.

[0043] Specifically, such as Figure 1As shown, the high-dimensional encoded quantum random number generator includes an entangled photon source (an entangled photon source is a type of single-photon source), a wavelength splitter, at least one photon encoding and detection module (in this embodiment, a single photon encoding and detection module is used as an example), and a data processing module. The entangled photon source is used to generate at least one entangled photon pair with a wavelength combination (λa & λb), such as 1539.77 nm and 1560.61 nm. In practice, entangled photon sources can typically generate entangled photon pairs with multiple wavelength combinations (λ1a & λ1b, λ2a & λ2b, ..., λna & λnb), such as 1539.97nm & 1560.41nm, 1539.57nm & 1560.81nm, 1539.77nm & 1560.61nm, and 1539.37nm & 1561.01nm. These will be described in detail in subsequent embodiments. This embodiment will take an entangled photon pair with one wavelength combination (1539.77nm & 1560.61nm) as an example, which requires a photon encoding and detection module.

[0044] A wavelength splitter is connected to an entangled photon source to separate the two photons in an entangled photon pair, outputting them from the first photon end and the second photon end, respectively. In this embodiment, the wavelength splitter only needs to separate the two photons with different wavelengths in the photon pair, and can be a coarse wavelength division multiplexer, a filter, an MZ interferometer, an MMI interferometer, or other similar devices. Figure 2 The diagram shows a schematic of an on-chip MZ interferometer. The MZ interferometer includes a first coupler, a second coupler, two interferometer arms, and a phase modulator located on one of the interferometer arms. The phase modulator adjusts the phase change of the light on the interferometer arm to adjust the output path of the photon after passing through the MZ interferometer, i.e., whether it is output from the upper end or the lower end.

[0045] The photon encoding and detection module includes a first filter, a second filter, a dispersive device, a beam splitter module, a first photon detector D1, a second photon detector D2, and a third photon detector D3. The first and second filters are used to filter the light output from the first and second photon ends. Taking a 1539.77nm and 1560.61nm photon pair as an example, the main function of the first filter is to allow photons with a wavelength of 1539.77nm to pass through, while filtering out residual laser components and other stray noise in the optical path.

[0046] Photons passing through the second filter are directly output to the third photon detector. At this point, this path can be considered to have no dispersion or delay. The time when the photon arrives at the third photon detector is used as the reference zero point for the time when the photon arrives at the first and second photon detectors.

[0047] The dispersive device is connected to the first filter and used to time-spread the passing photons to m time modes. Taking a 1539.77nm photon as an example, the actual wavelength of the photon passing through the first filter may not be a perfect 1539.77nm, but rather 1539.75nm, 1539.76nm, 1539.78nm, or 1539.79nm. This wavelength jitter is generally much smaller than the wavelength difference (20nm) between different wavelength combinations. That is, the wavelength of a single photon could be any one of 1539.75nm, 1539.76nm, 1539.77nm, 1539.78nm, or 1539.79nm, existing in a superposition of five quantum states of these five wavelengths. After passing through the dispersive device, photons of different wavelengths, due to differences in propagation speed, are located in five different time periods at the time of exiting the dispersive device, corresponding to "m time modes," where m=5. (See reference...) Figure 4 and Figure 5 . Figure 4 This is a schematic diagram illustrating the effect of a dispersive device on photons of different frequencies. It is assumed that a pulse contains multiple photons, for example, three photons with wavelengths of 1539.76 nm, 1539.77 nm, and 1539.78 nm simultaneously within a time interval τ. (Refer to...) Figure 4 The three vertical lines of different colors are to indicate that the wavelengths of the three photons are similar. After passing through the dispersive device, the three photons will be located in three time periods, which is equivalent to time broadening. Each time period can be regarded as a time pattern.

[0048] The assumption that a pulse contains three photons is hypothetical; such multi-photon situations may occur when the laser power is high. In actual laser power, the pulse after the first filter generally contains only one photon. Because the four-wave mixing in the entangled photon source is probabilistic, only one photon pair reaches the wavelength splitter each time, and only one photon remains after passing through the first filter. This photon's wavelength could be any of 1539.76nm, 1539.77nm, or 1539.78nm, and it exists in a quantum superposition of three states (wavelengths). Each photon can only be one of these wavelengths, and after passing through the dispersive device, the photon can only be located in one of the three time periods, and can only be one of the three time modes, such as... Figure 5 As shown.

[0049] The beam splitting module is connected to the output of the dispersive device and is used to perform high-dimensional time encoding on the passing photons. The beam splitting module includes n beam splitters connected in series, where n is a positive integer. Each beam splitter includes an upper input, a lower input, an upper output, and a lower output. The upper output of the i-th beam splitter is connected to the upper input of the (i+1)-th beam splitter by an i-th delay unit, or the lower output of the i-th beam splitter is connected to the lower input of the (i+1)-th beam splitter by an i-th delay unit, where i is an integer from 1 to n-1.

[0050] The photons entering the beam-splitting module are ultimately output from either the upper output of the nth beam splitter to the first photon detector or from the lower output of the nth beam splitter to the second photon detector. Depending on the different paths the photons take, the beam-splitting module broadens the photons to 2... n In each time period, photons are encoded into a total of m*2 n A time pattern.

[0051] Figure 6 This diagram illustrates different photon paths within the beam-splitting module in this application embodiment. To simplify the beam splitter structure, it is represented by a broken line. In the actual chip layout, the various parts of the beam splitter are connected and transitioned by smooth curves. Taking a four-beam-splitter configuration as an example, the first and second beam splitters have two connection paths: an upper connecting arm between the upper output of the first beam splitter and the upper input of the second beam splitter, and a lower connecting arm between the lower output of the first beam splitter and the lower input of the second beam splitter, as shown in the figure. A first delay unit is provided on the lower connecting arm. In other embodiments of this application, the first delay unit can also be located on the upper connecting arm. Similarly, a second delay unit is provided between the second and third beam splitters, and a third delay unit is provided between the third and fourth beam splitters. When the beam-splitting module has n beam splitters, an (n-1)th delay unit is provided between the (n-1)th and (n-n)th beam splitters. The photon delay of the first delay unit is 2. 0 *Δt, the photon delay of the second delay unit is 2. 1 *Δt, the photon delay of the third delay unit is 2. 2 *Δt, the photon delay of the (n-1)th delay unit is 2 n-1 *Δt. The four beam splitters contain a total of 3 pairs of upper and lower connecting arms, with 2 3 =8 paths, the photon is finally output from the upper end of the output of the nth beam splitter to the first photon detector or from the lower end of the output of the nth beam splitter to the second photon detector, a total of 2*2 3 =2 4 =16 paths. (Reference) Figure 7Photons can have eight modes each when entering from either the upper or lower output end. Combined with the three time modes already present before the photons enter the beam splitter module, the photon encoding dimension of the entire system is 3 * 16 = 48 dimensions. For computational convenience, the parameters of the dispersive device can be designed so that the photons, after passing through the dispersive device, have m = 2... k There are 2 time patterns, and the total photon encoding dimension is 2. k *2 n .

[0052] The data processing module connects to the photon encoding and detection module. It is used to calculate the times when the first and second photon detectors detect photons, with the time point when the third photon detector detects the photon as the zero point, and convert it into the number of bits log2(2). k *2 n Quantum random numbers. Taking n=4, k=3 as an example, after the photon passes through the dispersive device and the beam splitter module, the total encoding dimension is 2. (4+3) =128, the detection of one photon can be converted into a bit count of log2(2). (4+3) The quantum random number generator has a value of 7. For example, in traditional technical solutions, the detection of a photon can only yield 0 or 1, while in the technical solution of this application, the detection of a photon can yield a random number in the range of 1 to 128, which is represented in binary as a random binary number between 00000000 and 11111111, thereby improving the quantum random number generation rate of the quantum random number generator.

[0053] In other embodiments of this application, the entangled photon source includes a laser and a nonlinear medium connected in sequence. The nonlinear medium is one of a silicon-based waveguide, silicon nanowires, a silicon microring resonator, or a periodically polarized lithium niobate waveguide. The silicon-based waveguide, silicon nanowires, and silicon microring resonator are all on-chip devices that can be integrated onto a silicon chip. The periodically polarized lithium niobate waveguide is an on-chip device of the lithium niobate chip. Subsequent wavelength splitters, filters, dispersive devices, and beam-splitting modules can all be designed as silicon-based on-chip devices or lithium niobate on-chip devices, thereby integrating all devices between the laser and the detector onto a single chip, reducing the overall system size and cost, improving optical path stability, and reducing coupling losses between devices.

[0054] The dispersive device in this application embodiment can be a dispersive waveguide or a dispersive grating, which can be integrated into a chip. Different photons will be separated in time after passing through the dispersive waveguide or dispersive grating, thereby generating multiple time modes.

[0055] In the embodiments of this application, the first filter and the second filter can be on-chip micro-ring resonators, such as... Figure 3As shown, photons enter from the in end and are then coupled into the microring. Photons of a specific wavelength resonate in the microring resonator and are output from the out end, while photons of other wavelengths are discarded from the drop end. The microring resonator modulates the resonant frequency (wavelength) of the microring by controlling the electric field generated by the control electrodes, thereby allowing photons of a specific wavelength to pass through.

[0056] The optical delay of each delay unit is an integer multiple of Δt. In this embodiment, the optical delay of the first delay unit for the photon is Δt, and the optical delay of the i-th delay unit for the photon is 2. i-1 *Δt, the optical delay of the photon for the (n-1)th delay unit is 2. n-1 *Δt. Taking n=4 as an example, the delays for different paths are different, namely 1*Δt, 2*Δt, 3*Δt, 4*Δt, 5*Δt, 6*Δt, and 7*Δt. Including zero delay, there are 8 paths and 8 delays. Combining the different output ports, there are a total of 16 modes.

[0057] To further utilize all possible entangled photon pairs generated by the entangled photon source, multiple photon encoding and detection modules can be configured, in which case the wavelength splitter becomes a dense wavelength division multiplexer. For example... Figure 8 As shown, the entangled photon source provides entangled photon pairs with various wavelength combinations (λ1a&λ1b, λ2a&λ2b, ..., λna&λnb). The dense wavelength division multiplexer divides the incoming photons into multiple sets of entangled photon pairs (of course, only one set of photon pairs is used at a time, but it is impossible to determine which set it is each time). Each photon encoding and detection module processes one type of entangled photon pair with wavelength combinations (λia&λib), and only one pair of entangled photon pairs is used at a time. The data processing module processes the detection results of each photon encoding and detection module, finally obtaining n sets of bits with a total number of log2(m*2). n This design ensures that every pair of entangled photons generated by the entangled photon source can be utilized, maximizing the use of the entangled photon source's resources and further improving the generation rate of quantum random numbers.

[0058] As mentioned earlier, practical entangled photon sources can generally generate entangled photon pairs with multiple wavelength combinations, such as entangled photon pairs with wavelengths of 1539.57nm & 1560.81nm, 1539.77nm & 1560.61nm, and 1539.97nm & 1560.41nm. (See reference...) Figure 9 . Figure 9This diagram illustrates the interaction of multiple dispersive devices within multiple photon encoding and detection modules with photons of different frequencies. It presents a hypothetical scenario: three wavelengths of photons are present around 1539.57nm (e.g., 1539.56nm, 1539.57nm, 1539.58nm), corresponding to the three blue photons in the diagram; three wavelengths are present around 1539.77nm, corresponding to the three green photons; and three wavelengths are present around 1539.97nm, corresponding to the three red photons. After passing through a dense wavelength division multiplexer, the three entangled photon pairs are separated into three photon encoding and detection modules, as shown below. Figure 9 The first column consists of three pulses. The first pulse corresponds to three photons of different wavelengths around 1539.57nm, and so on. Subsequently, the three photons from each pulse are input to the first filter and dispersive device. The photons with a wavelength of 1560.81nm enter the second filter and are then directly transmitted to the third photon detector for detection.

[0059] After passing through the dispersion module, photons of the three wavelengths around 1539.57nm will be broadened into three time periods, resulting in three time modes. Photons of the three wavelengths around 1539.77nm will be broadened into three time periods, resulting in three time modes. Photons of the three wavelengths around 1539.97nm will be broadened into three time periods, resulting in three time modes.

[0060] Figure 9 The scenario shown is a hypothetical one, and this multiphoton situation may occur when the laser power is high. The explanation below... Figure 9 This is for ease of understanding. In a practical scenario with appropriate laser power, each pulse contains only one photon and one wavelength. (Refer to...) Figure 10 After passing through the dispersion module, photons with a wavelength of 1539.57nm will broaden to one of the three time intervals, falling into one of the three time modes. Photons with wavelengths of 1539.77nm and 1539.97nm will broaden in the same way, each falling into one of the three time modes. The path encoding method for subsequent photons in the beam splitting module remains unchanged. The data processing module processes the encoding of each photon and the detection results from the detection module, finally obtaining n sets of bits with a total number of log2(m*2). n Quantum random numbers.

[0061] This application also provides a quantum random number generation method, applied to the aforementioned high-dimensional encoded quantum random number generator, the flowchart of which is shown below. Figure 11 As shown, the method includes:

[0062] An entangled photon source generates at least one entangled photon pair with a wavelength combination (λa & λb);

[0063] The wavelength splitter separates the two photons in an entangled photon pair and outputs them from the first photon end and the second photon end, respectively;

[0064] The first filter and the second filter filter the light output from the first photon end and the second photon end, respectively.

[0065] Photons passing through the second filter are directly output to the third photon detector for photon detection;

[0066] Photons passing through the first filter enter the dispersive device, which time-widens the photons to m time intervals, corresponding to m time patterns, where m is a positive integer.

[0067] The beam-splitting module further encodes the photons output from the dispersive device in high dimensions, and outputs the photons either from the upper output of the nth beam splitter to the first photon detector or from the lower output of the nth beam splitter to the second photon detector. Depending on the different paths the photons take, the beam-splitting module broadens the photons to 2... n In each time period, photons are encoded into a total of m*2 n A time pattern;

[0068] The data processing module calculates the detection times of the first and second photon detectors, using the time when the third photon detector detects the photon as the zero point, and converts it into a bit count of log2(m*2). n Quantum random numbers.

[0069] Furthermore, this high-dimensional encoded quantum random number generator may also include multiple photon encoding and detection modules, a dense wavelength division multiplexer (DWDM) for the wavelength splitter, and an entangled photon source to provide entangled photon pairs with various wavelength combinations. Each photon encoding and detection module processes one type of entangled photon pair with a specific wavelength combination. The data processing module processes the detection results from each photon encoding and detection module, ultimately obtaining n sets of bits with a total number of log2(m*2). n Quantum random numbers.

[0070] Furthermore, to further improve the randomness quality of quantum random numbers, the following operation can be adopted: the data processing module selects at least two sets of n sets of quantum random numbers, performs an XOR operation on each set, and outputs the results. These two sets of random numbers can be arbitrarily selected. For example, if a total of 8 sets of quantum random numbers are obtained, an XOR operation is performed between every two sets of quantum random numbers to obtain 4 new sets of quantum random numbers with better randomness. Alternatively, these 4 sets of quantum random numbers can be further XORed between every two sets to obtain 2 sets of quantum random numbers, and then further XORed to obtain a single set of quantum random numbers. The process of obtaining 1 set of quantum random numbers from 8 sets of quantum random numbers through multiple XOR operations can be seen as a process of exchanging quantity for quality. In the basic embodiment, the quantum random numbers obtained by high-dimensional encoding are already higher qubits. Multiple sets of quantum random numbers are obtained through a dense wavelength division multiplexing (DWDM) and then merged into one set through XOR processing. The entire process can be seen as a dual improvement in the rate and quality of quantum random numbers.

[0071] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0073] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-dimensional encoded quantum random number generator, characterized in that, It includes an entangled photon source, a wavelength beam splitter, at least one photon encoding and detection module, and a data processing module; An entangled photon source is used to generate entangled photon pairs with at least one wavelength combination. The wavelength splitter is connected to the entangled photon source and is used to separate the two photons in the entangled photon pair and output them from the first photon end and the second photon end, respectively. The photon encoding and detection module includes a first filter, a second filter, a dispersive device, a beam splitter module, a first photon detector, a second photon detector, and a third photon detector. The first and second filters are used to filter the light output from the first and second photon ends. The photons passing through the second filter are directly output to the third photon detector. The dispersive device is connected to the first filter and is used to time-spread the passing photons to m time intervals, corresponding to m time patterns, where m is a positive integer. The beam splitting module is connected to the output of the dispersive device and is used to perform high-dimensional time encoding on the passing photons. The beam splitting module includes n beam splitters connected in series, where n is a positive integer. Each beam splitter includes an upper input, a lower input, an upper output, and a lower output. The upper output of the i-th beam splitter is connected to the upper input of the (i+1)-th beam splitter by an i-th delay unit, or the lower output of the i-th beam splitter is connected to the lower input of the (i+1)-th beam splitter by an i-th delay unit, where i is an integer from 1 to n-1. The photons entering the beam-splitting module are ultimately output from either the upper output of the nth beam splitter to the first photon detector or from the lower output of the nth beam splitter to the second photon detector. Depending on the different paths the photons take, the beam-splitting module broadens the photons to 2... n In each time period, photons are encoded into a total of m*2 n A time pattern; The data processing module connects to the photon encoding and detection module. It calculates the times when the first and second photon detectors detected the photon, using the time of detection by the third photon detector as zero, and converts this time into a bit count of log2(m*2). n Quantum random numbers.

2. The high-dimensional encoded quantum random number generator according to claim 1, characterized in that, The entangled photon source includes a laser and a nonlinear medium connected in sequence. The nonlinear medium is one of silicon-based waveguides, silicon nanowires, silicon microring resonators, and periodically polarized lithium niobate waveguides.

3. The high-dimensional encoded quantum random number generator according to claim 1, characterized in that, The wavelength splitter is an on-chip MZ interferometer or an on-chip multimode interferometer.

4. The high-dimensional encoded quantum random number generator according to claim 1, characterized in that, The first filter and the second filter are on-chip micro-ring resonators.

5. The high-dimensional encoded quantum random number generator according to claim 1, characterized in that, The dispersive device is a dispersive waveguide or a dispersive grating.

6. The high-dimensional encoded quantum random number generator according to claim 1, characterized in that, The optical delay of the photon by the first delay unit is Δt, and the optical delay of the photon by the i-th delay unit is 2. i-1 *Δt.

7. The high-dimensional encoded quantum random number generator according to claim 1, characterized in that, Includes multiple photon coding and detection modules; The wavelength splitter is a dense wavelength division multiplexer, and the entangled photon source is used to provide entangled photon pairs with multiple different wavelength combinations. Each photon encoding and detection module processes entangled photon pairs with one wavelength combination. The data processing module processes the detection results of each photon encoding and detection module, finally obtaining n sets of bits with a total number of log2(m*2). n Quantum random numbers.

8. A method for generating quantum random numbers, characterized in that, Applied to the high-dimensional encoded quantum random number generator as described in any one of claims 1 to 7, the method comprises: An entangled photon source generates entangled photon pairs with at least one wavelength combination; The wavelength splitter separates the two photons in an entangled photon pair and outputs them from the first photon end and the second photon end, respectively; The first filter and the second filter filter the light output from the first photon end and the second photon end, respectively. Photons passing through the second filter are directly output to the third photon detector for photon detection; Photons passing through the first filter enter the dispersive device, which time-widens the photons to m time intervals, corresponding to m time patterns, where m is a positive integer. The beam-splitting module further encodes the photons output from the dispersive device in high dimensions, and outputs the photons either from the upper output of the nth beam splitter to the first photon detector or from the lower output of the nth beam splitter to the second photon detector. Depending on the different paths the photons take, the beam-splitting module broadens the photons to 2... n In each time period, photons are encoded into a total of m*2 n A time pattern; The data processing module calculates the detection times of the first and second photon detectors, using the time when the third photon detector detects the photon as the zero point, and converts it into a bit count of log2(m*2). n Quantum random numbers.

9. The quantum random number generation method according to claim 8, characterized in that, The high-dimensional encoded quantum random number generator includes multiple photon encoding and detection modules. The wavelength splitter is a dense wavelength division multiplexer. The entangled photon source is used to provide entangled photon pairs with multiple different wavelength combinations. Each photon encoding and detection module processes entangled photon pairs with one wavelength combination. The data processing module processes the detection results of each photon encoding and detection module, finally obtaining n sets of bits with a total number of log2(m*2). n Quantum random numbers.

10. The quantum random number generation method according to claim 9, characterized in that, The data processing module selects at least two of the n sets of quantum random numbers, performs XOR processing on them, and outputs the results.

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