CN112346710A - A quantum random number generator chip and design method - Google Patents

Abstract

The invention discloses a quantum random number generator chip and a design method, wherein the chip comprises: optical chip, transimpedance amplifier chip and the microcontroller chip that connects gradually, wherein: the optical chip comprises a continuous laser, an optical beam splitter, a first optical attenuator, a second optical attenuator, a first photoelectric detector and a second photoelectric detector; the microcontroller chip comprises a first digital-to-analog converter, a second digital-to-analog converter, an analog-to-digital converter and a processor; the transimpedance amplifier chip comprises a transimpedance amplifier; the quantum random number generator chip is obtained by packaging the optical chip, the transimpedance amplifier chip and the microcontroller chip. The optical chip and the microcontroller chip are packaged in one chip by a systematic packaging method, so that the volume of the quantum random number system is greatly reduced, the stability of the system and the structure is greatly improved, the power consumption and the cost are reduced, and the application range and the application scene are improved.

Description

A quantum random number generator chip and design method

technical field

The invention belongs to the technical field of quantum random number generation, and in particular relates to a quantum random number generator chip and a design method.

Background technique

Random number is a widely used basic resource, which has extensive and important applications in many fields such as quantum communication, cryptography, gaming industry, Monte Carlo simulation, numerical computing, random sampling, neural network computing, traditional information security and so on. The randomness guarantee of the quantum random number generator originates from the principle of quantum physics. It generates a true random number by measuring the inherent random characteristics in the quantum physical system, which is unpredictable, irreproducible and unbiased. Its randomness is determined by the quantum Compared with other random number generation technologies, the basic principles of mechanics have more advantages, so it has higher security, and is especially suitable for application scenarios with high randomness requirements.

Various schemes can realize quantum random number generator, such as photon path selection scheme, photon arrival time scheme, laser phase fluctuation scheme and quantum random number scheme independent of measurement device, etc. At present, the quantum random number system based on discrete optoelectronic devices generally has the disadvantages of high price, large size, high power consumption, poor stability, and low reliability, etc., and it is difficult to meet the requirements of the popular application of quantum random numbers. For example, in the above example, the single-photon path selection scheme and the photon arrival time scheme have a bit rate of the order of Mbps, and a single-photon detector is used in the system, which is large in size and high in cost; the laser phase fluctuation scheme has a bit rate up to 10Gbps or more, but because the optical interferometer is included in this solution, the system is bulky and sensitive to vibration and temperature, which is not conducive to practical application.

At present, the light source and reading circuit of another existing random number scheme are independent external structures, and the reading circuit is a field programmable array, which is large in size and has high power consumption; at the same time, the light source and optical chip of the above technical scheme It is fixed by fitting, and the structural stability is poor.

It can be seen from the above examples that quantum random number application scenarios require random number solutions with low cost, low power consumption, small size, high stability and reliability.

To sum up, the defects of the prior art are: the current quantum random number system is expensive, bulky, high power consumption, poor stability, low reliability, and it is difficult to meet the requirements of the popular application of quantum random numbers.

SUMMARY OF THE INVENTION

Therefore, in the prior art, a quantum random number system based on discrete optoelectronic devices is expensive, bulky, high power consumption, poor stability, and low reliability, and it is difficult to meet the requirements for the popularization and application of quantum random numbers.

For this reason, an improved quantum random number generator chip and design method are very much needed, so that the real-time quantum random number generator can be realized by a single chip, and the optical chip and the post-processing can be integrated by the method of hybrid integration and system-in-package. The terminal reading circuit chip is integrated in one package, and finally the single-chip real-time quantum random number generator can meet the practical application requirements of low cost, low power consumption, small size, high stability and reliability.

In this context, embodiments of the present invention are expected to provide a quantum random number generator chip and design method.

In a first aspect of the embodiments of the present invention, a quantum random number generator chip is provided, comprising: an optical chip, a transimpedance amplifier chip and a microcontroller chip connected in sequence, wherein: the above-mentioned optical chip includes a continuous laser, a light A beam splitter, a first optical attenuator, a second optical attenuator, a first photodetector and a second photodetector; the microcontroller chip includes a first digital-to-analog converter, a second digital-to-analog converter, an analog-to-digital converter A converter and a processor; the above-mentioned transimpedance amplifier chip includes a transimpedance amplifier;

In an embodiment of the present invention, the two output ends of the optical beam splitter are respectively independently connected to the first optical attenuator and the second optical attenuator; the output end of the first optical attenuator is connected to the first photodetector The output end of the second optical attenuator is connected to the second photodetector.

In another embodiment of the present invention, the optical beam splitter is provided with two input ends, one of the input ends of the optical beam splitter is connected to the continuous laser, and the other input end is vacant as a vacuum state optical input end.

In yet another embodiment of the present invention, the output ends of the first photodetector and the second photodetector of the optical chip are connected to the transimpedance amplifier of the transimpedance amplifier chip.

In yet another embodiment of the present invention, the above-mentioned processor is respectively connected to the first digital-to-analog converter, the second digital-to-analog converter, and the analog-to-digital converter.

In yet another embodiment of the present invention, the output end of the first digital-to-analog converter is connected to the first optical attenuator, and the output end of the second digital-to-analog converter is connected to the second optical attenuator.

In yet another embodiment of the present invention, the input end of the analog-to-digital converter is connected to the transimpedance amplifier.

In yet another embodiment of the present invention, the size of the above-mentioned optical chip is 2cm×1cm or 5mm×3mm.

In yet another embodiment of the present invention, the size of the transimpedance amplifier chip is 1 mm×1 mm; the size of the microcontroller chip is 3 mm×4 mm.

In a second aspect of the embodiments of the present invention, a method for designing the above quantum random number generator chip is provided, comprising: attenuating the above-mentioned optical beam splitter, the first optical attenuator and the second optical beam by means of photon integration The optical device is integrated into the optical waveguide chip; the above-mentioned continuous laser, the first photodetector, the second photodetector and the optical waveguide chip are mixed and integrated by the method of hybrid integration to form an optical chip; the above-mentioned optical chip, The transimpedance amplifier chip and the microcontroller chip are packaged to form a quantum random number generator chip.

According to the quantum random number generator chip and the design method according to the embodiment of the present invention, the light source, the optical path design and the detector in the vacuum state quantum random number scheme are integrated on an optical chip by adopting the method of photon integration and hybrid integration. The systematic packaging method encapsulates the microcontroller chip and the optical chip in one chip, which greatly reduces the volume of the quantum random number system, greatly improves the stability of the system and structure, reduces power consumption and cost, and improves the The scope of application and application scenarios.

Description of drawings

FIG. 1 is a schematic structural diagram of a quantum random number generator chip provided by an embodiment of the present invention.

In the figure: 1, optical chip; 2, transimpedance amplifier chip; 3, microcontroller chip; 11, continuous laser; 12, vacuum state light; 13, optical beam splitter; 14, first optical attenuator; 15, first photodetector; 16, second optical attenuator; 17, second photodetector; 21, transimpedance amplifier; 31, first digital-to-analog converter; 32, analog-to-digital converter; 33, second digital-to-analog converter Converter; 34. Processor.

FIG. 2 is a flowchart of a method for designing a quantum random number generator chip provided by an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The quantum random number generator chip of the exemplary embodiment of the present invention will be described below with reference to FIG. 1 .

As shown in FIG. 1 , the quantum random number generator chip provided by the embodiment of the present invention includes: an optical chip 1 , a transimpedance amplifier chip 2 , a microcontroller chip 3 , a continuous laser 11 , a vacuum state light 12 , and an optical beam splitter 13 , the first optical attenuator 14, the first photodetector 15, the second optical attenuator 16, the second photodetector 17, the transimpedance amplifier 21, the first digital-to-analog converter 31, the analog-to-digital converter 32, the second A digital-to-analog converter 33 and a processor 34 .

In an embodiment of the present invention, the quantum random number generator chip is obtained by the optical chip 1, the transimpedance amplifier chip 2 and the microcontroller chip 3 through system level packaging;

The optical chip 1 includes a continuous laser 11, an optical beam splitter 13, a first optical attenuator 14, a second optical attenuator 16, a first photodetector 15 and a second photodetector 17; the microcontroller chip 3 includes a first optical attenuator 14 A digital-to-analog converter 31 , a second digital-to-analog converter 33 , an analog-to-digital converter 32 and a processor 34 ; the transimpedance amplifier chip 2 includes a transimpedance amplifier 21 .

In this embodiment, the two output ends of the optical beam splitter 13 are respectively independently connected to the first optical attenuator 14 and the second optical attenuator 16; the output end of the first optical attenuator 14 is connected to the first photodetector 15, The output ends of the two optical attenuators 16 are connected to the second photodetector 17 . The optical beam splitter 13 is provided with two input ends, one input end of the optical beam splitter 13 is connected to the CW laser 11 , and the other input end is vacant, serving as the input end of the vacuum state light 12 .

In this embodiment, the output ends of the first photodetector 15 and the second photodetector 17 of the optical chip 1 are connected to the transimpedance amplifier 21 of the transimpedance amplifier chip 2 .

In this embodiment, the processor 34 is connected to the first digital-to-analog converter 31 , the second digital-to-analog converter 33 and the analog-to-digital converter 32 respectively. The output end of the first digital-to-analog converter 31 is connected to the first optical attenuator 14 , and the output end of the second digital-to-analog converter 33 is connected to the second optical attenuator 16 . The input end of the analog-to-digital converter 32 is connected to the transimpedance amplifier 21 .

In this embodiment, the size of the optical chip 1 is 2cm×1cm or 5mm×3mm, the size of the transimpedance amplifier chip 2 is 1mm×1mm, and the size of the microcontroller chip 3 is 3mm×4mm; 1. The sizes of the transimpedance amplifier chip 2 and the microcontroller chip 3 include but are not limited to the above specific sizes, and the size of the quantum random number generator chip can be adjusted according to usage and design requirements.

According to the embodiment of the present invention, the single-chip real-time quantum random number generator scheme is theoretically feasible by the system-level packaging of the optical chip 1, the transimpedance amplifier chip 2 and the microcontroller chip 3, and the system-level integrated quantum random number generator The number generator reaches the order of 1cm, which greatly reduces the size of the quantum random number system and improves the application scope and application scenarios.

After the chip of the exemplary embodiment of the present invention is introduced, next, the design method of the quantum random number generator chip of the exemplary embodiment of the present invention will be described with reference to FIG. 2 .

As shown in FIG. 2 , the method for designing a quantum random number generator chip according to an embodiment of the present invention includes operations S101 to S103 .

In operation S101, the optical beam splitter 13, the first optical attenuator 14 and the second optical attenuator 16 are integrated on the optical waveguide chip by means of photonic integration.

In operation S102 , the continuous laser 11 , the first photodetector 15 , the second photodetector 17 , and the optical waveguide chip are mixed and integrated by a hybrid integration method to form the optical chip 1 .

In operation S103, the optical chip 1, the transimpedance amplifier chip 2 and the microcontroller chip 3 are packaged by the method of systematic packaging to form a quantum random number generator chip.

According to the embodiment of the present invention, the light source, the optical path design and the detector in the vacuum state quantum random number scheme are integrated on an optical chip 1 by adopting the method of photon integration and hybrid integration, and the micro-controller is integrated by the method of systematic packaging. The device chip 3 and the optical chip 1 are packaged in one chip, which makes the integration of the quantum random number system higher, reduces the structural layout and wiring difficulty between the structures, greatly reduces the volume of the quantum random number system, and greatly reduces the size of the quantum random number system. Improved system and structural stability while reducing power consumption and cost.

In order to further facilitate understanding, the following introduces the working process and working principle of a quantum random number generator chip design method shown in FIG. 1 .

1. Workflow

The continuous laser is input to one end of the optical beam splitter in the optical chip, and the other end of the input of the optical beam splitter is vacant, serving as the light input end in a vacuum state. Each of the two output ports of the optical beam splitter has an optical attenuator. The optical beam splitter and the optical attenuator divide the input light into two beams of light with an intensity ratio of 50/50, and the two beams of light enter two photodetectors respectively. Photoelectric conversion process; after the optical signal is converted into two current signals and subtracted (homodyne detection), it enters the transimpedance amplifier, amplifies the weak high-frequency current signal and converts it into a voltage signal; this voltage signal is generated by quantum fluctuations The signal enters the analog-to-digital converter and is post-processed by the processor in the microcontroller to obtain a quantum random number generated in real time.

2. Working principle

Quantum fluctuations exist in coherent light fields, which satisfy the principle of least uncertainty in amplitude and phase. This random number scheme is essentially a quantum fluctuation of coherent states. In the embodiment of the present invention, the photodetector is used to perform homodyne detection on the two paths of light after being split by the optical beam splitter, and the randomness is embodied.

经过光分束器和两路衰减器后，两路光变为

则有下列关系：One input of the optical beam splitter is a local oscillator light source (ie, continuous laser), and the other is vacant (ie, vacuum state light). If we assume that the two input quantum states are

After passing through the beam splitter and the two attenuators, the two paths of light become

There are the following relationships:

分别对应本振光源和真空态。对于50∶50的分光比的光分束器

在分束器输出端则有：in,

Corresponding to the local oscillator light source and the vacuum state, respectively. Beamsplitter for 50:50 splitting ratio

At the output of the beam splitter there are:

即为真空态；In the above formula,

is the vacuum state;

After photoelectric conversion, the current passing through the first and second photodetectors is:

分别对应两路输入光电探测器的光强；

增加了上标“+”代表

量子态的厄米共轭。电流值应等于量子效率与光强大小的乘积，两路电流的差为：In the above formula, k is the quantum efficiency of the photodetector,

Corresponding to the light intensity of the two input photodetectors respectively;

Added superscript "+" to represent

Hermitian conjugation of quantum states. The current value should be equal to the product of quantum efficiency and light intensity, and the difference between the two currents is:

can prove:

where <Δi ² > corresponds to quantum noise σ _q ² , which is reflected in the results of homodyne detection. In the embodiment of the present invention, the noise distribution obtained by the electronic readout circuit is divided into two parts, quantum noise σ _q ² and classical noise σ _e ² , namely

σ _total ² =σ _q ² +σ _e ² (eight)

A continuous laser is a coherent light source whose average number of photons is recorded as μ. For using a coherent light source, the photon number n obeys a Poisson distribution whose distribution is given by:

Among them, the average photon number μ needs to be optimized through theoretical analysis and experimental results, and this experimental parameter is usually controlled by adjusting the luminous intensity of the light source and the adjustable attenuator.

After the homodyne detection of the photodetection results by the two photodetectors, the number of photons obeys the Skellam distribution, and its distribution is given by the following formula:

p _k =P(n ₁ -n ₂ =k)=e ^-2μ I _k (2μ) (ten)

Among them, I _k (2μ) is the modified Bessel function; n ₁ and n ₂ respectively correspond to the average photon number of the two paths of light, and are also two parameters of the Skellam distribution, which determine the shape of the distribution.

In the embodiment of the present invention, the distribution of quantum noise can be obtained through the above calculation.

The classical noise obeys the Gaussian distribution in the system, and the proportion of quantum noise can be calculated only by measuring the classical noise σ _e ² when there is no light input.

The minimum entropy is calculated by calculating the distribution of quantum noise. Randomness is quantified by minimum entropy, which is defined as:

H _∞ = -log ₂ p _max (11)

where _pmax is the probability of the most likely outcome. The random numbers of vacuum state fluctuations obey the Skellam distribution, and through the aforementioned quantum noise variance σ _q ² , p _max can be obtained, thereby calculating the minimum entropy.

In the final random number post-processing, the T0eplitz matrix algorithm based on fast Fourier transform is used, and the matrix size is n×m, that is, the final random number of m bits can be extracted from the original quantum random number data of n bits, and the following conditions are satisfied Relationship: n/m≤H _∞ . According to the minimum entropy result, the above processing can obtain the final quantum random number, whose randomness originates from the basic principles of quantum physics and is verifiable by information theory.

In the above scheme, the minimum entropy of the original data is calculated according to the measurement result, and the measurement result can be obtained inside the microcontroller, thereby realizing the accurate estimation of the minimum entropy. After the original data is post-processed, the final quantum random number of the vacuum state fluctuation can be obtained in real time. Through the above scheme, high-speed and stable quantum random numbers can be obtained.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (10)

1. a quantum random number generator chip, is characterized in that, comprises: optical chip, transimpedance amplifier chip and microcontroller chip connected successively, wherein: The optical chip includes a continuous laser, an optical beam splitter, a first optical attenuator, a second optical attenuator, a first photodetector and a second photodetector; The microcontroller chip includes a first digital-to-analog converter, a second digital-to-analog converter, an analog-to-digital converter and a processor; The transimpedance amplifier chip includes a transimpedance amplifier; Wherein, the optical chip, the transimpedance amplifier chip and the microcontroller chip are packaged to obtain the quantum random number generator chip. 2. The quantum random number generator chip according to claim 1, wherein the two output ends of the optical beam splitter are respectively independently connected to the first optical attenuator and the second optical attenuator; the The output end of the first optical attenuator is connected to the first photodetector, and the output end of the second optical attenuator is connected to the second photodetector. 3. The quantum random number generator chip of claim 1, wherein the optical beam splitter is provided with two input ends, and an input end of the optical beam splitter is connected with the continuous laser, The other input is vacant as a vacuum light input. 4. The quantum random number generator chip according to claim 1, wherein the output end of the first photodetector and the output end of the second photodetector of the optical chip are respectively connected with the transimpedance amplifier. The chip's transimpedance amplifier is connected. 5 . The quantum random number generator chip of claim 1 , wherein the processor is respectively connected to the first digital-to-analog converter, the second digital-to-analog converter, and the analog-to-digital converter. 6 . 6 . The quantum random number generator chip according to claim 1 , wherein the output end of the first digital-to-analog converter is connected to the first optical attenuator, and the output of the second digital-to-analog converter is connected to the first optical attenuator. The output end is connected to the second optical attenuator. 7 . The quantum random number generator chip of claim 1 , wherein the input end of the analog-to-digital converter is connected to the transimpedance amplifier. 8 . 8 . The quantum random number generator chip of claim 1 , wherein the size of the optical chip is 2 cm×1 cm or 5 mm×3 mm. 9 . 9 . The quantum random number generator chip according to claim 1 , wherein the size of the transimpedance amplifier chip is 1 mm×1 mm; the size of the microcontroller chip is 3 mm×4 mm. 10 . 10. A method for designing a quantum random number generator chip as claimed in claim 1-9, characterized in that, comprising: Integrating the optical beam splitter, the first optical attenuator and the second optical attenuator onto an optical waveguide chip by a photonic integration method; The continuous laser, the first photodetector, the second photodetector and the optical waveguide chip are mixed and integrated by a hybrid integration method to form the optical chip; The optical chip, the transimpedance amplifier chip and the microcontroller chip are packaged by a systematic packaging method to form a quantum random number generator chip.

Images