An error mitigation device and method for continuous variable optical systems

Abstract

The application provides an error mitigation device and method for a continuous variable optical system, which is used for removing errors in a quantum signal generated by the continuous variable optical system to obtain a measurement result of the quantum signal without phase damping noise, and the error mitigation device comprises at least a noise modulation unit, a detection unit and a data processing unit, wherein the noise modulation unit generates a plurality of phase-different voltage signals based on a plurality of noise parameters configured by a user, and performs phase modulation on the quantum signal based on the generated voltage signals to obtain a plurality of phase-modulated quantum signals; the detection unit is used for detecting each phase-modulated quantum signal to obtain measurement results of all the phase-modulated quantum signals; and the data processing unit is used for determining the measurement result of the quantum signal without phase damping noise by using an extrapolation method based on the noise parameters configured by the user and all the measurement results detected by the detection unit.

Description

Technical Field

[0001] This invention relates to the field of quantum computing, specifically to quantum error mitigation techniques, and more specifically to an error mitigation device and method for continuous variable optical systems. Background Technology

[0002] The operation of continuous-variable optical systems is highly dependent on the accuracy of quantum signals. However, quantum signals are extremely susceptible to environmental interference, such as temperature fluctuations and electromagnetic radiation. These disturbances inevitably introduce noise, leading to deviations or even errors in the calculation results. To eliminate errors in continuous-variable optical systems, quantum error mitigation techniques have emerged. Quantum error mitigation is a technique applicable to medium-scale noisy quantum devices (NISQs) for processing system noise. Its working principle is as follows: measurements are first performed on a noisy quantum computer, and then the measurement results of the quantum signal under noise-free conditions are estimated through classical post-processing.

[0003] Current research on quantum error mitigation techniques in continuous-variable optical systems lags significantly behind that in discrete-variable systems. Existing schemes primarily focus on eliminating photon loss noise. Specifically, they employ probabilistic error cancellation (PEC) techniques, analytically deriving the inverse mapping of photon loss channels and decomposing them into physically operable channel combinations with negative coefficients (such as noiseless amplification and photon subtraction operations), followed by Monte Carlo sampling to achieve unbiased estimation. While these schemes can theoretically completely eliminate loss errors, their physical implementation relies on highly complex operations: 1) Noiseless amplification requires nondeterministic quantum processes (such as subspace looping operations in the Zavatta scheme), with resource consumption increasing exponentially with the number of modes; 2) Photon subtraction requires multi-port beam splitters and photon number-resolved detectors (PNRDs), resulting in complex experimental setups with poor scalability; 3) They are only applicable to specific initial states (cat states, single-photon states, etc.). More importantly, current research almost completely ignores another important noise source in continuous-variable systems—phase-damped noise (originating from phase decoherence caused by environmental coupling), for which there are currently no effective mitigation schemes.

[0004] In summary, existing quantum error mitigation techniques suffer from three major problems. First, their research scope is limited, focusing only on photon loss noise and lacking systematic research on phase-damped noise, resulting in gaps in continuous-variable noise coverage. Second, experimental implementation faces significant obstacles. Mainstream PEC schemes rely on photon number-resolved detection and nondeterministic noise-free amplification, far exceeding the capabilities of basic linear optics. This necessitates expensive and complex devices such as quantum memories and high-precision single-photon detectors, significantly increasing technical difficulty and cost. Third, the methods lack universality, requiring customized inverse channel decomposition for specific initial states such as squeezed vacuum states and cat states, making it difficult to generalize to arbitrary continuous-variable quantum states. Therefore, there is an urgent need for a quantum error mitigation scheme that can simultaneously suppress photon loss and phase-damped noise, requires no complex quantum devices, and is universally applicable to any continuous-variable quantum state.

[0005] It should be noted that the background information presented here is only for illustrating relevant information about the present invention to aid in understanding the technical solutions of the present invention, and does not imply that the relevant information is necessarily prior art. In the absence of evidence indicating that the relevant information was disclosed before the filing date of this invention, the relevant information should not be considered prior art. Summary of the Invention

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide an error mitigation device and method for continuous variable optical systems.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] According to a first aspect of the present invention, an error mitigation device for a continuous variable optical system is provided. The continuous variable optical system continuously generates the same quantum signal, each generated quantum signal containing an error caused by phase damping noise of the continuous variable optical system. The error mitigation device removes the error in the quantum signal generated by the continuous variable optical system to obtain a measurement result of the quantum signal without phase damping noise. The error mitigation device includes a noise modulation unit, a detection unit, and a data processing unit. The noise modulation unit receives multiple noise parameters configured by a user, generates multiple voltage signals with different phases based on the configured noise parameters, and receives the quantum signal generated by the continuous variable optical system and performs phase modulation on the received quantum signal based on the generated voltage signal to obtain multiple phase-modulated quantum signals. Each noise parameter corresponds to multiple voltage signals, and each voltage signal is used to perform phase modulation on one quantum signal. The detection unit detects each phase-modulated quantum signal to obtain a measurement result of all phase-modulated quantum signals. The data processing unit uses an extrapolation method based on all user-configured noise parameters and all measurement results detected by the detection unit to determine the measurement result of the quantum signal generated by the continuous variable optical system without phase damping noise.

[0009] Preferably, the noise modulation unit is configured with a noise parameter input module, a random voltage generation module, and a phase modulation module, wherein: the noise parameter input module is used to provide noise parameter configuration services so that users can configure multiple noise parameters; the random voltage generation module is used to randomly generate multiple voltage signals corresponding to each noise parameter input by the user; the phase modulation module is used to receive the quantum signal generated by the continuous variable optical system and to perform phase modulation on the received quantum signal based on the voltage signal generated by the random voltage generation module, wherein one voltage signal is used to perform phase modulation on one quantum signal.

[0010] Preferably, the phases of the multiple voltage signals corresponding to each noise parameter generated by the random voltage generation module follow a Gaussian distribution.

[0011] Preferably, the phase modulation module is configured to perform phase modulation on the quantum signal in the following manner:

[0012]

[0013] in, Indicates the user configuration of the first One noise parameter, The density matrix representing the quantum states of a quantum signal in the absence of phase-damped noise. Indicates the phase modulator with noise parameters The density matrix of the quantum signal obtained by phase modulation of the quantum signal by the corresponding voltage signal. The rows representing the elements in the density matrix of a quantum signal. The columns represent the elements in the density matrix of a quantum signal.

[0014] Preferably, the detection unit is configured to: use a balanced null detector to perform conventional null detection on the phase-damped modulated quantum signal to obtain the measurement result of the phase-modulated quantum signal.

[0015] Preferably, the extrapolation method is as follows: based on all measurement results detected by the detection unit, the average value of the measurement results corresponding to each noise parameter is determined, wherein the average value of the measurement results corresponding to each noise parameter is the average value of the measurement results of all quantity signals obtained by phase modulation of the voltage signal corresponding to the noise parameter; a set of equations is established based on the average value of all determined measurement results and the noise parameters configured by the user; the established set of equations is solved to obtain the measurement results of the quantum signal without phase damping noise.

[0016] Preferably, the system of equations to be solved is:

[0017]

[0018] in, Indicates the user configuration of the first The average value of the measurement results of all phase-modulated quantum signals corresponding to the noise parameter. Indicates the user configuration of the first Noise parameters, This represents the measurement result of the quantum signal without phase-damped noise. Indicates the first One unknown coefficient, This represents the total number of noise parameters input by the user. This indicates the preset precision.

[0019] According to a second aspect of the present invention, an error mitigation method for a continuous variable optical system is proposed to remove errors in a quantum signal generated by a target continuous variable optical system, so as to obtain a measurement result of the quantum signal generated by the target continuous variable optical system without phase damping noise. The method includes: step S1, obtaining an error mitigation device as described in the first aspect of the present invention and configuring multiple noise parameters; step S2, continuously generating the same quantum signal by the target continuous variable optical system, and using the error mitigation device configured with noise parameters in step S1 to remove errors in the quantum signal to obtain a measurement result of the quantum signal without phase damping noise.

[0020] According to a third aspect of the invention, a computer-readable storage medium is provided having a computer program stored thereon, the computer program being executable by a processor to implement the method described in the second aspect of the invention.

[0021] According to a fourth aspect of the invention, an electronic device is provided, comprising: one or more processors; and a memory for storing executable instructions; wherein the one or more processors are configured to implement the method of the second aspect of the invention by executing the executable instructions.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] This invention proposes an error mitigation device for continuous variable optical systems. This device can precisely control phase damping noise of different intensities using only linear optical devices. By extrapolating measurement results under multiple noise levels, it can effectively estimate and mitigate phase damping errors in quantum signals generated by continuous variable optical systems without the need for complex quantum devices, thus achieving low-cost and easily scalable continuous variable quantum signal error suppression. Attached Figure Description

[0024] The embodiments of the present invention will be further described below with reference to the accompanying drawings, wherein:

[0025] Figure 1 This is a schematic diagram of an error mitigation device for a continuous variable optical system according to an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] As mentioned in the background section, existing quantum error mitigation techniques suffer from three major problems. First, their research scope is limited, focusing only on photon loss noise and lacking systematic research on phase-damped noise, resulting in gaps in continuous-variable noise coverage. Second, experimental implementation faces significant obstacles. Mainstream PEC schemes rely on photon number-resolved detection and nondeterministic noise-free amplification, far exceeding the capabilities of basic linear optics. This necessitates expensive and complex devices such as quantum memories and high-precision single-photon detectors, significantly increasing technical difficulty and cost. Third, the methods lack universality, requiring customized inverse channel decomposition for specific initial states such as squeezed vacuum states and cat states, making it difficult to generalize to arbitrary continuous-variable quantum states. Therefore, there is an urgent need for a quantum error mitigation scheme that can simultaneously suppress photon loss and phase-damped noise, requires no complex quantum devices, and is universally applicable to any continuous-variable quantum state.

[0028] To address the aforementioned issues, this invention proposes an error mitigation scheme for continuous variable optical systems. This scheme can precisely control phase damping noise of different intensities using only linear optical devices. By extrapolating the measurement results under multiple noise levels, the measurement results of the quantum signal without phase damping noise can be obtained. The entire process can effectively estimate and mitigate phase damping errors without the need for complex quantum devices.

[0029] To better illustrate the feasibility of the present invention, the formation process of the present invention will be briefly described below.

[0030] Through in-depth research on continuous-variable optical systems, the inventors discovered that: on the one hand, extrapolation methods widely used in discrete-variable systems (such as Richardson extrapolation) have not been effectively transferred to the continuous-variable domain; on the other hand, through in-depth analysis of the physical nature of phase-damped noise, phase-damped noise is equivalent to linear optical Gaussian random phase modulation. Therefore, by actively adjusting the continuous scaling of noise intensity, it is possible to modulate quantum signals under multiple noise intensities and measure the modulated quantum signals. Furthermore, extrapolation can be used to reverse-engineer the measurement results of the quantum signals without phase-damped noise. Applying random Gaussian phase damping to a quantum state can be expressed by the following formula:

[0031]

[0032] in, The density matrix representing the quantum states of a quantum signal in the absence of phase-damped noise. Indicates noise parameters, It is a photon number operator. This indicates that an optical mode is applied. Phase, further, can be derived from the above equation to obtain the following formula:

[0033]

[0034] In this invention, the formula on the right-hand side of the second equation is obtained by performing a Fourier transform on the Gaussian function in the formula on the right-hand side of the first equation, and the result is still a Gaussian function. Furthermore, since phase-damped noise is equivalent to linear optical Gaussian random phase modulation, this invention directly controls the phase-damping intensity based on a Gaussian random distribution, enabling continuous scaling of noise intensity. Based on these findings, the quantum signal can be adjusted under multiple noise intensities, and the adjusted quantum signal can be measured. Then, the measurement result of the quantum signal under the influence of phase-damped noise can be calculated using an extrapolation method.

[0035] According to an embodiment of the present invention, based on the above derivation, the present invention proposes an error mitigation device for a continuous variable optical system, wherein the continuous variable optical system continuously generates the same quantum signal, and each generated quantum signal contains an error caused by the fixed phase damping noise of the continuous variable optical system. The error mitigation device proposed in this invention is used to remove the error in the quantum signal generated by the continuous variable optical system to obtain the measurement result of the quantum signal without phase damping noise. See also Figure 1 The error mitigation device proposed in this invention includes a noise modulation unit, a detection unit, and a data processing unit. The noise modulation unit receives multiple noise parameters configured by the user and generates multiple voltage signals with different phases based on the configured noise parameters. It also receives a quantum signal generated by a continuous-variable optical system and performs phase modulation on the received quantum signal based on the generated voltage signal to obtain multiple phase-modulated quantum signals. Each noise parameter corresponds to multiple voltage signals, and each voltage signal is used to perform phase modulation on one quantum signal. The detection unit detects each phase-modulated quantum signal to obtain the measurement results of all phase-modulated quantum signals. The data processing unit uses an extrapolation method based on all user-configured noise parameters and all measurement results detected by the detection unit to determine the measurement results of the quantum signal generated by the continuous-variable optical system without phase-damped noise.

[0036] To better understand the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0037] According to one embodiment of the present invention, see still Figure 1 In the error mitigation device proposed in this invention, the noise modulation unit includes a noise parameter input module, a random voltage generation module, and a phase modulation module. The noise parameter input module provides a noise parameter configuration service, allowing the user to configure multiple noise parameters. The random voltage generation module randomly generates multiple voltage signals corresponding to each noise parameter input by the user. The phase modulation module receives quantum signals generated by a continuous-variable optical system and performs phase modulation on the received quantum signals based on the voltage signals generated by the random voltage generation module, wherein one voltage signal is used to phase modulate one quantum signal.

[0038] According to one embodiment of the present invention, in this invention, the phases of the multiple voltage signals corresponding to each noise parameter generated by the random voltage generation module follow a Gaussian distribution. Specifically, the voltage generator generates a set of voltage signals based on a configured noise parameter to obtain multiple sets of voltage signals, wherein the phase distribution of the generated voltage signals should satisfy... , It follows a Gaussian random distribution. Indicates noise parameters, Let θ represent the phase. Taking Γ=0.1 as an example, the generated voltage signal phase θ satisfies a Gaussian probability density function: .

[0039] According to one embodiment of the present invention, in this invention, a phase modulation module loads a voltage signal generated by a random voltage generation module and performs phase modulation on the quantum signal passing through the phase modulation module, so that the off-diagonal elements of the quantum signal density matrix are arranged according to... Attenuation is performed to complete the phase modulation of the quantum signal. Specifically, the phase modulation module modulates only one quantum signal for each applied voltage signal. The phase modulation process of the quantum signal can be represented by the following formula:

[0040]

[0041] in, Indicates the user configuration of the first One noise parameter, The density matrix representing the quantum states of a quantum signal in the absence of phase-damped noise. Indicates the phase modulator with noise parameters The density matrix of the quantum signal obtained by phase modulation of the quantum signal by the corresponding voltage signal. The rows representing the elements in the density matrix of a quantum signal. The columns represent the elements in the density matrix of a quantum signal.

[0042] To facilitate understanding of the modulation process of quantum signals by the phase modulation module, a detailed description with examples will be provided below.

[0043] Assuming the quantum signal is a coherent state (A coherent state is a state with an uncertain number of photons but a stable phase correlation), the density matrix of the quantum signal is ρ= Matrix element When noise parameters and When the attenuation factor is Matrix element is When noise parameters and Time (e.g.) The attenuation factor is: Matrix element .

[0044] According to one embodiment of the present invention, a detection unit is deployed at the output end of the phase modulation module. The detection unit is used to detect the phase-modulated quantum signal to obtain the measurement result of the phase-modulated quantum signal. In the present invention, the detection unit uses a balanced zero-difference detector to perform conventional zero-difference detection on the phase-damped modulated quantum signal to obtain the measurement result of the phase-modulated quantum signal. It should be noted that the detection unit can also be constructed using other detectors that use conventional zero-difference detection as the detection method.

[0045] According to one embodiment of the present invention, multiple quantum signals generated by a continuous variable optical system are sequentially modulated by a noise modulation unit and detected by a detection unit to obtain measurement results of multiple phase-modulated quantum signals. Each quantum signal corresponds to a voltage signal of a noise parameter. In this invention, the data processing unit, based on the Richardson extrapolation principle, constructs a system of linear equations using the obtained multiple quantum signals and user-configured noise parameters to solve for the measurement results of the quantum signals without phase-damped noise. The constructed linear equations are then solved to obtain the measurement results of the quantum signals without phase-damped noise. Specifically, firstly, a matrix equation is constructed based on all user-configured noise parameters and all measurement results detected by the detection unit:

[0046]

[0047] Then, performing matrix operations on the above equation yields a system of linear equations for solving the measurement results of the quantum signal without phase-damped noise. The system of linear equations is expressed as follows:

[0048]

[0049] in, Indicates the user configuration of the first The average of all measurements corresponding to the noise parameter. Indicates the user configuration of the first Noise parameters, This represents the measurement result of the quantum signal without phase-damped noise. Indicates the first One unknown coefficient, This represents the total number of noise parameters input by the user. This indicates the preset precision. This refers to the advanced remainder term. It should be noted that the remainder term can be ignored in the calculations of this invention. This serves as the measurement result for solving a system of equations to obtain a quantum signal without phase-damped noise.

[0050] According to an embodiment of the present invention, based on the above-described error mitigation device for a continuous variable optical system, the present invention proposes an error mitigation method for a continuous variable optical system implemented with the device. In summary, the method includes: step S1, acquiring the error mitigation device described above and configuring multiple noise parameters; step S2, controlling the target continuous variable optical system to continuously generate the same quantum signal, while using the error mitigation device with the noise parameters configured in step S1 to remove the error in each quantum signal, so as to obtain the measurement result of the quantum signal without phase damping noise.

[0051] To facilitate understanding of the error mitigation device for a continuous variable optical system proposed in this invention, the process of the device mitigating errors in a continuous variable optical system is described below with reference to specific examples.

[0052] Suppose there is a continuous variable optical system for quantum key distribution. The quantum signal generated by this system has fixed phase damping noise. The steps required to obtain the measurement result of the quantum signal generated by this continuous variable optical system without phase damping noise using the error mitigation device proposed in this invention include steps 1, 2 and 3, wherein the operation performed in each step is as follows.

[0053] Step 1: Device Preparation and Noise Parameter Configuration. Connect the quantum signal output of the continuous variable optical system to the input of the noise modulation unit (including a noise parameter input module, a random voltage generation module, and a phase modulation module) of the error mitigation device. Connect the output of the noise modulation unit to the detection unit (balanced zero-difference detector). The detection unit is connected to the data processing unit (a computer equipped with MATLAB data processing program) via a data cable. Through the noise parameter input module, the user configures three noise parameters: Γ1=0.1, Γ2=0.3, and Γ3=0.5 (k=3). Simultaneously, the preset accuracy r in the extrapolation method is configured as 2. It should be understood that the number and value of the above noise parameters and the value of the accuracy r are exemplary and should be configured by the implementer during the actual implementation. The more noise parameters configured and the higher the preset accuracy value in the extrapolation method, the higher the accuracy of the final measurement result of the quantum signal without phase-damped noise.

[0054] Step 2: Noise modulation and quantum signal detection enable the random voltage generation module to generate 100 voltage signals with phases following a Gaussian distribution for each noise parameter. Taking Γ1=0.1 as an example, the generated voltage signal phase θ satisfies the Gaussian probability density function: Similarly, voltage signal sets corresponding to Γ2 and Γ3 are generated. The continuous variable optical system continuously generates the same quantum signal, which sequentially enters the phase modulation module. The phase modulation module loads voltage signals one by one to modulate the phase of the quantum signal. For example, when loading a certain voltage signal corresponding to Γ1, according to the formula... Phase-damped modulation of the quantum signal yielded 300 phase-modulated quantum signals (3 noise parameters × 100 voltage signals). A balanced homodyne detector was used to perform homodyne detection on each modulated quantum signal to obtain the measurement results of the quantum state of each modulated quantum signal. ( (corresponding to 100 measurement results) , All measurement results are then transmitted to the data processing unit.

[0055] Step 3: Data Processing and Measurement Result Solving. The data processing unit averages the 100 measurement results corresponding to each noise parameter to obtain: =0.1 corresponding to the average value =0.85 (0.85 is an assumed value; the actual value is calculated from the probe data). =0.3 corresponding average value =0.62, =0.5 corresponding average value =0.41. According to the extrapolation formula... Establish a system of equations:

[0056]

[0057] Solving the above linear equations using matrix operations or the least squares method yields the measurement result ⟨O>=0.98 for the quantum signal generated by the continuous variable optical system without phase damping noise. It should be understood that the parameters in the above example are merely illustrative; in actual implementation, the data from the actual detection should prevail.

[0058] In summary, the error mitigation device for continuous variable optical systems proposed in this invention can precisely control phase damping noise of different intensities using only linear optical devices. By extrapolating measurement results under multiple noise levels, it can effectively estimate and mitigate phase damping errors without complex quantum devices, thereby achieving error suppression of quantum signals generated by low-cost and easily scalable continuous variable optical systems.

[0059] It should be noted that although the steps are described in a specific order above, it does not mean that the steps must be executed in the above specific order. In fact, some of these steps can be executed concurrently or even in a different order, as long as the required function can be achieved.

[0060] This invention can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of the invention.

[0061] Computer-readable storage media can be tangible devices that hold and store instructions for use by an instruction execution device. Computer-readable storage media can include, for example, but not limited to, electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof.

[0062] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An error mitigation device for a continuous variable optical system, the continuous variable optical system being configured to continuously generate identical quantum signals, an error caused by phase damping noise of the continuous variable optical system being present in each of the generated quantum signals, the error mitigation device being configured to remove the error in a quantum signal generated by the continuous variable optical system to obtain a measurement of the quantum signal as if the phase damping noise were not present, characterized in that, The error mitigation device comprises a noise modulation unit, a detection unit and a data processing unit, wherein The noise modulation unit is configured to receive a plurality of noise parameters configured by a user, generate a plurality of voltage signals with different phases based on the configured noise parameters, and receive quantum signals generated by a continuous variable optical system, and perform phase modulation on the received quantum signals based on the generated voltage signals to obtain a plurality of phase-modulated quantum signals, wherein each noise parameter corresponds to a plurality of voltage signals, and each voltage signal is used for phase modulation of one quantum signal, and the noise modulation unit is configured with a noise parameter input module, a random voltage generation module and a phase modulation module, wherein: The noise parameter input module is configured to provide a noise parameter configuration service to facilitate the user to configure a plurality of noise parameters; The random voltage generation module is configured to randomly generate a plurality of voltage signals corresponding to each noise parameter based on the user input, and the phases of the plurality of voltage signals corresponding to each noise parameter follow a Gaussian distribution; The phase modulation module is configured to receive the quantum signals generated by the continuous variable optical system, and perform phase modulation on the received quantum signals in a preset manner based on the voltage signals generated by the random voltage generation module, wherein one voltage signal is used for phase modulation of one quantum signal, and the preset manner is: wherein denotes a user-configured set of noise parameters, denotes a density matrix of a quantum state of the quantum signal in the absence of phase-damping noise, denotes a phase modulator with noise parameters denotes a density matrix of the quantum signal after phase modulation of the quantum signal by the corresponding voltage signal, denotes a row of elements in the density matrix of the quantum signal, denotes a column of elements in the density matrix of the quantum signal; The detection unit is configured to detect each phase-modulated quantum signal to obtain measurement results of all phase-modulated quantum signals; The data processing unit is configured to determine the measurement results of the quantum signals generated by the continuous variable optical system without phase damping noise based on all noise parameters configured by the user and all measurement results detected by the detection unit by using an extrapolation method.

2. The apparatus of claim 1, wherein, The detection unit is configured to perform regular homodyne detection on the phase-damped quantum signals by using a balanced homodyne detector to obtain the measurement results of the phase-modulated quantum signals.

3. The apparatus of claim 2, wherein, The extrapolation method is: Based on all measurement results detected by the detection unit, determine the average value of the measurement results corresponding to each noise parameter, wherein the average value of the measurement results corresponding to each noise parameter is the average value of the measurement results of all quantum signals obtained by phase modulation of the voltage signal corresponding to the noise parameter; Based on all determined average values of the measurement results and the noise parameters configured by the user, establish an equation set; Solve the established equation set to obtain the measurement results of the quantum signals without phase damping noise.

4. The apparatus of claim 3, wherein, The solving equation set is: wherein, represents the first measurement result of the quantum signal corresponding to the noise parameter, represents the first noise parameter, represents the measurement result of the quantum signal without phase damping noise, represents the first unknown coefficient, represents the total number of noise parameters input by the user, represents the preset precision.

5. An error mitigation method for a continuous variable optical system, for removing errors in a quantum signal generated by a target continuous variable optical system to obtain a measurement of the quantum signal generated by the target continuous variable optical system in the absence of phase damping noise, the method comprising: determining a plurality of error correction parameters for the target continuous variable optical system; and applying the error correction parameters to the quantum signal generated by the target continuous variable optical system to obtain the measurement of the quantum signal generated by the target continuous variable optical system in the absence of phase damping noise. The method comprises: Step S1, obtaining the error mitigation device according to any one of claims 1-4, and configuring a plurality of noise parameters; Step S2, causing the target continuous variable optical system to continuously generate the same quantum signal, and using the error mitigation device configured with the noise parameters in step S1 to remove the errors in the quantum signal to obtain the measurement results of the quantum signal without phase damping noise.

6. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and the computer program can be executed by a processor to implement the method of claim 5.

7. An electronic device, comprising: Comprise: One or more processors; And Memory, wherein the memory is used to store executable instructions; The one or more processors are configured to implement the method of claim 5 via execution of the executable instructions. The one or more processors are configured to implement the method of claim 5 via execution of the executable instructions.

Images