A photonic quantum variational quantum computing device
By using a variable quantum optical computing device and employing fiber optic modules and loss function adjustment techniques, the problem of limited qubits and high noise in the NISQ era has been solved, and stable quantum computing has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 粤港澳大湾区(广东)量子科学中心
- Filing Date
- 2026-03-27
- Publication Date
- 2026-05-29
AI Technical Summary
Existing quantum computing hardware is in the era of Noisy Medium Scale (NISQ), with a limited number of qubits and high noise, making it difficult to achieve fault-tolerant quantum computing.
A quantum variable quantum computing device is used, including a state preparation component, a computing component, and a measurement and detection component. Quantum logic calculation and measurement are realized through an optical fiber module. The quantum state preparation parameters are adjusted by using a loss function to gradually reduce the calculation error.
Enabling meaningful computational tasks under NISQ conditions improves the stability and accuracy of quantum computing and enables variable quantum computation.
Smart Images
Figure CN121920566B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of quantum computing technology, and in particular to an optical quantum variable quantum computing device based on optical quantum transmission. Background Technology
[0002] Quantum computing is considered a major technological revolution following classical computing. It utilizes properties such as quantum superposition, entanglement, and interference to achieve exponential speedups of classical algorithms on certain problems. Although groundbreaking quantum algorithms such as Shor's algorithm and Grover's algorithm have been theoretically proposed, running these fault-tolerant quantum algorithms on actual hardware requires millions of error-correctable qubits. However, current quantum hardware technology is still in the era of noisy intermediate-scale quantum (NISQ), with a limited number of usable qubits and high noise levels. Therefore, the realization of fault-tolerant quantum computing is still some time away.
[0003] Against this backdrop, researchers have proposed the technique of Variational Quantum Computing (VQC). This technique employs a quantum-classical hybrid architecture, combining the powerful representational capabilities of quantum circuits with the efficient search capabilities of classical optimization, thereby enabling meaningful computational tasks to be performed even under NISQ conditions. Since the initial proposal of VQE (Variational Quantum Eigensolver) around 2014, VQC has gradually developed into a core method in fields such as quantum chemistry, combinatorial optimization, and quantum machine learning.
[0004] In variational quantum computing, parameterized quantum circuits (PQCs) are typically used, which are sequences of quantum gates with adjustable parameters. PQCs are usually composed of multiple quantum gates, such as single-qubit rotation gates and multi-qubit entangled gates (e.g., CNOT gates), allowing for flexible exploration in exponential-dimensional space by adjusting the rotation angle. Summary of the Invention
[0005] In view of this, this application provides a quantum variable quantum computing device, which enables quantum variable quantum computing based on quantum transmission.
[0006] This application provides a quantum variable quantum computing device, comprising: a state preparation component, a computing component, and a measurement and detection component;
[0007] The quantum state preparation component is used to adjust the preparation parameters for preparing quantum states according to the adjustment command; receive the light beam input from the light source, prepare the corresponding quantum state according to the received light beam, and transmit the prepared quantum state to the computing component;
[0008] The computing component is used to perform quantum logic calculations on the received quantum state and transmit the calculated quantum state to the measurement and detection component.
[0009] The measurement and detection component is used to prepare the required measurement basis, use the measurement basis to measure the quantum state output by the computing component, and output the measurement result; and calculate the loss function based on the measurement result and the expected result. When the loss function is greater than a preset threshold, an adjustment command is output to the state preparation component based on the value of the loss function.
[0010] Furthermore, the computing component includes: a first optical fiber module, a second optical fiber module, and a third optical fiber module;
[0011] The input end of the first optical fiber module is connected to the output end of the state preparation component, the first output end of the first optical fiber module is connected to the second input end of the second optical fiber module, and the second output end of the first optical fiber module is connected to the first input end of the third optical fiber module.
[0012] The second output terminal of the second optical fiber module is connected to the first input terminal of the measurement and detection component;
[0013] The first output terminal of the third optical fiber module is connected to the second input terminal of the measurement and detection component;
[0014] The first optical fiber module is a type 1 optical fiber module; the second and third optical fiber modules are both type 2 optical fiber modules;
[0015] The first type of optical fiber module is used to output the superposition state of the first quantum state and the second quantum state from one of its output terminals and output the first quantum state from another of its output terminals when it receives the superposition state of the first quantum state and the second quantum state. The intensity of the first quantum state output by the output terminal that outputs the superposition state is half the intensity of the first quantum state output by the other output terminal.
[0016] The second type of optical fiber module is used to output a superposition state of the first quantum state and the second quantum state from one of its output terminals and output the first quantum state from another of its output terminals when one of its input terminals receives the first quantum state and the other input terminal receives the second quantum state. The intensity of the first quantum state output by the output terminal that outputs the superposition state is half the intensity of the first quantum state output by the other output terminal.
[0017] Furthermore, the first type of optical fiber module includes: a first polarization beam splitter, a second polarization beam splitter, a third polarization beam splitter, a first partial polarization beam splitter, and a second partial polarization beam splitter;
[0018] The two output terminals of the first polarization beam splitter are respectively connected to the input terminals of the first partial polarization beam splitter and the second partial polarization beam splitter;
[0019] The first output terminal of the first partial polarization beam splitter is connected to the first input terminal of the second polarization beam splitter; the second output terminal of the first partial polarization beam splitter is connected to the first input terminal of the third polarization beam splitter.
[0020] The first output terminal of the second partial polarization beam splitter is connected to the second input terminal of the second partial polarization beam splitter; the second output terminal of the second partial polarization beam splitter is connected to the second input terminal of the third polarization beam splitter.
[0021] Furthermore, the first polarization beam splitter is a polarization beam splitter with two input terminals and two output terminals;
[0022] The second and third polarization beamsplitters are polarization beamsplitters with two input terminals and one output terminal.
[0023] Furthermore, the first and second partial polarization beamsplitters are partial polarization beamsplitters with one input and two outputs.
[0024] Furthermore, the first type of optical fiber module includes: a first component and a second component;
[0025] The first component includes: a first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, and a first polarization beam splitter crystal;
[0026] The ports of the first optical fiber, the second optical fiber, the third optical fiber, and the fourth optical fiber are respectively connected to the four sides of the first polarization beam splitter crystal in a clockwise order.
[0027] The angle between the slow axis of the port of the first optical fiber and the slow axis of the first polarization beam splitter crystal is 63.5°.
[0028] The angle between the slow axis of the second optical fiber port and the slow axis of the first polarization beam splitter crystal is 90°.
[0029] The angle between the slow axis of the ports of the third and fourth optical fibers and the slow axis of the first polarization beam splitter crystal is 0°.
[0030] The second component includes: a fifth optical fiber, a sixth optical fiber, a seventh optical fiber, an eighth optical fiber, and a second polarization beam splitter crystal;
[0031] The ports of the fifth, sixth, seventh, and eighth optical fibers are sequentially connected to the four sides of the second polarization beam splitter crystal in a clockwise order.
[0032] The angle between the slow axis of the ports of the fifth, sixth, seventh, and eighth optical fibers and the slow axis of the second polarization beam splitter crystal is 0°.
[0033] The other end of the sixth optical fiber is connected to the other end of the first optical fiber; the other end of the seventh optical fiber is connected to the other end of the fourth optical fiber.
[0034] Furthermore, the second type of fiber optic module includes: a fourth polarization beam splitter, a fifth polarization beam splitter, and a first beam splitter;
[0035] The first output terminal of the fourth polarization beam splitter is connected to the input terminal of the first beam splitter, and the second output terminal is connected to the second input terminal of the fifth polarization beam splitter.
[0036] The second output terminal of the first beam splitter is connected to the first input terminal of the fifth polarization beam splitter; the beam splitting ratio of the first beam splitter is 1:2.
[0037] Furthermore, the second type of fiber optic module includes: a sixth polarization beam splitter, a seventh polarization beam splitter, a second beam splitter, and a third beam splitter;
[0038] The first output terminal of the sixth polarization beam splitter is connected to the input terminal of the second beam splitter, and the second output terminal is connected to the second input terminal of the seventh polarization beam splitter.
[0039] The second output terminal of the second beam splitter is connected to the input terminal of the third beam splitter;
[0040] The second output terminal of the third beam splitter is connected to the first input terminal of the seventh polarization beam splitter;
[0041] The splitting ratio of the second and third beam splitters is 1:1.
[0042] Furthermore, the measurement and detection component includes: a measurement base module, a detection module, and a control module;
[0043] The measurement base module is used to prepare the required measurement base and transmit the prepared measurement base to the detection module;
[0044] The detection module is used to measure the quantum state output by the computing component using the received measurement basis, and output the measurement result;
[0045] The control module is used to calculate a loss function based on the measurement results and expected results. When the loss function is greater than a preset threshold, it outputs an adjustment command to the state preparation component based on the value of the loss function.
[0046] Furthermore, the first quantum state is a horizontally polarized state H or a |0> state;
[0047] The second quantum state is either a vertically polarized state V or a |1> state.
[0048] As can be seen from the above technical solution, in the optical quantum variable quantum computing device based on optical quantum transmission in this application, since a state preparation component, a computing component, and a measurement and detection component are set, the corresponding variable quantum calculation can be performed through the above-mentioned optical quantum variable quantum computing device. Attached Figure Description
[0049] Figure 1 This is a schematic diagram of the structure of a quantum variable quantum computing device based on quantum transmission in a specific embodiment of this application.
[0050] Figure 2 This is a schematic diagram of the computing component in a specific embodiment of this application.
[0051] Figure 3 This is a schematic diagram of the first type of optical fiber module in a specific embodiment of this application.
[0052] Figure 4 This is a schematic diagram of the first type of optical fiber module in another specific embodiment of this application.
[0053] Figure 5 This is a schematic diagram of the second type of optical fiber module in a specific embodiment of this application.
[0054] Figure 6 This is a schematic diagram of the second type of optical fiber module in another specific embodiment of this application.
[0055] Figure 7 A schematic diagram of the first type of optical fiber module in a specific embodiment of this application. Figure 1 .
[0056] Figure 8 A schematic diagram of the first type of optical fiber module in a specific embodiment of this application. Figure 2 .
[0057] Figure 9 This is a schematic diagram of the structure of a first type of optical fiber module in another specific embodiment of this application.
[0058] Figure 10 A schematic diagram of the principle of the first component in a specific embodiment of this application. Figure 1 .
[0059] Figure 11 A schematic diagram of the principle of the first component in a specific embodiment of this application. Figure 2 .
[0060] Figure 12 This is a schematic diagram illustrating the effect of a first type of optical fiber module in a specific embodiment of this application.
[0061] Figure 13 This is a schematic diagram of the effect of the first type of optical fiber module in another specific embodiment of this application.
[0062] Figure 14 This is a schematic diagram of the structure of a second type of optical fiber module in a specific embodiment of this application.
[0063] Figure 15 This is a schematic diagram of the structure of a second type of optical fiber module in another specific embodiment of this application. Detailed Implementation
[0064] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.
[0065] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0066] Figure 1 This is a schematic diagram of the structure of a quantum variable quantum computing device based on quantum transmission in a specific embodiment of this application. Figure 1 As shown, the optical quantum variable quantum computing device based on optical quantum transmission in this application may include: a state preparation component 11, a computing component 12, and a measurement and detection component 13;
[0067] The quantum state preparation component 11 is used to adjust the preparation parameters for preparing quantum states according to the adjustment command; receive the light beam input from the light source, prepare the corresponding quantum state according to the received light beam, and transmit the prepared quantum state to the computing component 12;
[0068] The computing component 12 is used to perform quantum logic calculations on the received quantum state and transmit the calculated quantum state to the measurement and detection component 13.
[0069] The measurement and detection component 13 is used to prepare the required measurement base, use the measurement base to measure the quantum state output by the computing component 12, and output the measurement result; and calculate the loss function based on the measurement result and the expected result. When the loss function is greater than a preset threshold, an adjustment command is output to the state preparation component 11 based on the value of the loss function.
[0070] In the aforementioned quantum variable quantum computing device of this application, after receiving a light beam from a light source, the state preparation component 11 can prepare a corresponding quantum state based on the received light beam, and then output the prepared quantum state to the computing component 12. Additionally, the state preparation component 11 can adjust the preparation parameters used to prepare the quantum state according to the adjustment command sent by the measurement and detection component 13, so that the corresponding quantum state can be prepared subsequently based on the adjusted preparation parameters and the received light beam. The computing component 12 can perform corresponding quantum logic calculation operations based on the received quantum state, and then output the operation result (i.e., the quantum state obtained after the quantum logic calculation operation) to the measurement and detection component 13. The measurement and detection component 13 can prepare the required measurement basis, and then use the prepared measurement basis to measure the quantum state output by the computing component 12, and output the measurement result. Simultaneously, it can calculate the corresponding loss function based on the measurement result and the expected result. When the loss function is greater than a preset threshold, it can output an adjustment command to the state preparation component 11 based on the value of the loss function to adjust the preparation parameters used to prepare the quantum state in the state preparation component 11. By continuously adjusting the preparation parameters in the adjustment state preparation component 11, the value of the loss function will gradually decrease, and the measurement result output by the measurement and detection component 13 will gradually converge to the corresponding fluctuation range. When the value of the loss function is less than or equal to a preset threshold, it can be considered that the measurement result is actually relatively stable (e.g., it has converged to the pre-required fluctuation range), so the operation can be stopped, and no more adjustment commands will be output to the state preparation component 11; at this time, the measurement result currently output by the measurement and detection component 13 can be used as the required calculation result. Therefore, the above-described quantum variable quantum computing device can perform corresponding variable quantum calculations. For example, the above-described quantum variable quantum computing device can be used to calculate a system of equations with one or more variables, thereby obtaining the solution to the system of equations.
[0071] In addition, the above-mentioned measurement and detection component 13 can be implemented in various specific ways in the technical solution of this application.
[0072] For example, as an example, in a specific embodiment of this application, the measurement and detection component 13 may include: a measurement base module 131, a detection module 132, and a control module 133;
[0073] The measurement base module 131 is used to prepare the required measurement base and transmit the prepared measurement base to the detection module 132;
[0074] The detection module 132 is used to measure the quantum state output by the computing component 12 using the received measurement basis, and output the measurement result;
[0075] The control module 133 is used to calculate a loss function based on the measurement results and expected results. When the loss function is greater than a preset threshold, it outputs an adjustment command to the state preparation component 11 based on the value of the loss function.
[0076] In addition, in the technical solution of this application, the expected result and the loss function corresponding to the expected result can be preset according to the needs of the actual application scenario, and the threshold corresponding to the loss function can be preset so that when the value of the loss function is less than or equal to the preset threshold, the measurement result output by the measurement detection component 13 will converge to the required fluctuation range.
[0077] Furthermore, the computing component described above can be implemented in various specific ways according to the needs of actual applications. The following will use one or more specific methods as examples to provide a detailed description of the technical solution of this application.
[0078] For example, as an example, such as Figure 2 As shown, in a specific embodiment of this application, the computing component 12 may include: a first optical fiber module 121, a second optical fiber module 122, and a third optical fiber module 123;
[0079] The input end of the first optical fiber module 121 is connected to the output end of the state preparation component 11, the first output end 213 of the first optical fiber module 121 is connected to the second input end 212 of the second optical fiber module 122, and the second output end 214 of the first optical fiber module 121 is connected to the first input end 211 of the third optical fiber module 123.
[0080] The second output terminal 214 of the second optical fiber module 122 is connected to the first input terminal of the measurement and detection component 13;
[0081] The first output terminal 213 of the third optical fiber module 123 is connected to the second input terminal of the measurement and detection component 13;
[0082] The first optical fiber module 121 is a first type of optical fiber module; the second optical fiber module 122 and the third optical fiber module 123 are both second type of optical fiber modules;
[0083] The first type of optical fiber module is used to output the superposition state of the first quantum state and the second quantum state from one of its output terminals and output the first quantum state from another of its output terminals when it receives the superposition state of the first quantum state and the second quantum state. The intensity of the first quantum state output by the output terminal that outputs the superposition state is half the intensity of the first quantum state output by the other output terminal.
[0084] The second type of optical fiber module is used to output a superposition state of the first quantum state and the second quantum state from one of its output terminals and output the first quantum state from another of its output terminals when one of its input terminals receives the first quantum state and the other input terminal receives the second quantum state. The intensity of the first quantum state output by the output terminal that outputs the superposition state is half the intensity of the first quantum state output by the other output terminal.
[0085] In addition, in the technical solution of this application, the first quantum state and / or the second quantum state can be predetermined according to the needs of the actual application scenario.
[0086] For example, as an illustration, in a specific embodiment of this application, the first quantum state may be a horizontally polarized state H or a |0> state; the second quantum state may be a vertically polarized state V or a |1> state. Alternatively, the second quantum state may be a horizontally polarized state H or a |0> state; and the first quantum state may be a vertically polarized state V or a |1> state.
[0087] Of course, the first quantum state and the second quantum state can also be other suitable quantum states, which will not be listed here.
[0088] For example, as an example, in a specific embodiment of this application, when the first type of optical fiber module receives a superposition of a first quantum state (e.g., a horizontally polarized state H or a |0> state) and a second quantum state (e.g., a vertically polarized state V or a |1> state) at its first input terminal 211, it can output a superposition of the first and second quantum states (e.g., a 1 / 3H+V quantum state) from its first output terminal 213 and output a first quantum state (e.g., a 2 / 3H quantum state) from its second output terminal 214, and the intensity of the first quantum state output from its second output terminal 214 is twice the intensity of the first quantum state output from its first output terminal 213 (e.g., as shown in the image). Figure 3 (as shown)
[0089] When its second input terminal 212 receives a superposition of a first quantum state (e.g., a horizontally polarized state H or a |0> state) and a second quantum state (e.g., a vertically polarized state V or a |1> state), it can output the superposition of the first and second quantum states (e.g., a 1 / 3H+V quantum state) from its second output terminal 214, and output the first quantum state (e.g., a 2 / 3H quantum state) from its first output terminal 213. The intensity of the first quantum state H output from its first output terminal 213 is twice the intensity of the first quantum state H output from its second output terminal 214 (e.g., as shown in the image). Figure 4 (As shown).
[0090] For example, in one specific embodiment of this application, when the second type of optical fiber module receives a first quantum state (e.g., a horizontally polarized state H or a |0> state) at its first input terminal 211 and a second quantum state (e.g., a vertically polarized state V or a |1> state) at its second input terminal 212, it can output a superposition state of the first and second quantum states (e.g., a 1 / 3H+V quantum state) from its second output terminal 214, and output a first quantum state (e.g., a 2 / 3H quantum state) from its first output terminal 213. The intensity of the first quantum state output from its first output terminal 213 is twice the intensity of the first quantum state output from its second output terminal 214 (e.g., as shown in the image). Figure 5 (as shown)
[0091] When its first input terminal 211 receives a second quantum state (e.g., a vertically polarized state V or a |1> state) and its second input terminal 212 receives a first quantum state (e.g., a horizontally polarized state H or a |0> state), it can output a superposition state of the first and second quantum states (e.g., a 1 / 3H+V quantum state) from its first output terminal 213, and output a first quantum state (e.g., a 2 / 3H quantum state) from its second output terminal 214. The intensity of the first quantum state output from its second output terminal 214 is twice the intensity of the first quantum state output from its first output terminal 213 (e.g., as shown in the image). Figure 6 (As shown).
[0092] Additionally, as an example, in a specific embodiment of this application, in the aforementioned computing components, the first input terminal 211 and the first output terminal 213 of the second fiber optic module 122 can be left unused, and the second input terminal 212 and the second output terminal 214 of the third fiber optic module 123 can be left unused, such as... Figure 2 As shown.
[0093] Furthermore, the first type of optical fiber module described above can be implemented in various specific ways in the technical solution of this application. The following will use several specific methods as examples to provide a detailed description of the technical solution of this application.
[0094] For example, as an example, such as Figure 7 and Figure 8 As shown, in a specific embodiment of this application, the first type of optical fiber module may include: a first polarization beam splitter (PBS), a second PBS, a third PBS, a first partial polarization beam splitter (PPBS), and a second PPBS;
[0095] The two output terminals of the first PBS are connected to the input terminals of the first PPBS and the second PPBS, respectively.
[0096] The first output terminal of the first PPBS is connected to the first input terminal of the second PBS; the second output terminal of the first PPBS is connected to the first input terminal of the third PBS.
[0097] The first output terminal of the second PPBS is connected to the second input terminal of the second PPBS; the second output terminal of the second PPBS is connected to the second input terminal of the third PPBS.
[0098] Therefore, when the input end of the first type of optical fiber module receives the superposition state of the first quantum state H and the second quantum state V, the 1 / 3H+V quantum state and the 2 / 3H quantum state can be output from the output ends of the second PBS and the third PBS, respectively.
[0099] Additionally, as an example, in a specific embodiment of this application, the first PBS may be a PBS with two input terminals and two output terminals (which may be simply referred to as 2×2PBS), while the second PBS and the third PBS may be PBSs with two input terminals and one output terminal (which may be simply referred to as 1×2PBS); the first PBS and the second PBS may be PBSs with one input terminal and two output terminals (which may be simply referred to as 1×2PPBS).
[0100] For example, such as Figure 7As shown in a specific embodiment of this application, when the first input terminal of the first PBS receives a superposition of a first quantum state (e.g., a horizontally polarized state H or a |0> state) and a second quantum state (e.g., a vertically polarized state V or a |1> state), the first PBS can separate the first quantum state and the second quantum state and output them to the first PPBS and the second PPBS respectively. For example, the first PBS can output the first quantum state H to the second PPBS and output the second quantum state V to the first PPBS. Since the first PPBS receives the second quantum state V, it will output the received second quantum state V to the second PBS through its first output terminal, and its second output terminal will not output a quantum state to the third PBS. Since the second PPBS receives the first quantum state H, the first output terminal of the second PPBS will output a 1 / 3H quantum state (i.e., a quantum state with an intensity of 1 / 3 of the original first quantum state H) to the second PBS, and the second output terminal of the second PPBS will output a 2 / 3H quantum state (i.e., a quantum state with an intensity of 2 / 3 of the original first quantum state H) to the third PBS. Both the second PBS and the third PBS can be used as beam combiners. Therefore, the second PBS can combine the second quantum state V received at its first input terminal and the 1 / 3H quantum state received at its second input terminal into a 1 / 3H+V quantum state (i.e., a superposition of the 1 / 3H quantum state and the second quantum state V) and output it. The third PBS can output the 2 / 3H quantum state received at its second input terminal. At this time, the output ends of the second PBS and the third PBS serve as the two output ends of the first type of optical fiber module mentioned above, outputting the 1 / 3H+V quantum state and the 2 / 3H quantum state respectively.
[0101] For example, such as Figure 8As shown in a specific embodiment of this application, when the second input terminal of the first PBS receives a superposition of a first quantum state (e.g., a horizontally polarized state H or a |0> state) and a second quantum state (e.g., a vertically polarized state V or a |1> state), the first PBS can separate the first quantum state and the second quantum state and output them to the first PPBS and the second PPBS respectively. For example, the first PBS can output the first quantum state H to the first PPBS and output the second quantum state V to the second PPBS. Since the second PPBS receives the second quantum state V, the second PPBS will output the received second quantum state V to the third PBS through its second output terminal, and its first output terminal will not output a quantum state to the second PBS; since the first PPBS receives the first quantum state H, the first output terminal of the first PPBS will output a 2 / 3H quantum state (i.e., a quantum state with an intensity of 2 / 3 of the original first quantum state H) to the second PBS, and the second output terminal of the first PPBS will output a 1 / 3H quantum state (i.e., a quantum state with an intensity of 1 / 3 of the original first quantum state H) to the third PBS. The second PBS and the third PBS can both be used as bundle combiners. Therefore, the second PBS can output the 2 / 3H quantum state received at its first input end; the third PBS can combine the 1 / 3H quantum state received at its first input end and the second quantum state V received at its second input end into a 1 / 3H+V quantum state (i.e., a superposition of the 1 / 3H quantum state and the second quantum state V) and output it. At this time, the output ends of the second PBS and the third PBS serve as the two output ends of the first type of optical fiber module mentioned above, respectively outputting the 2 / 3H quantum state and the 1 / 3H+V quantum state.
[0102] For example, as an example, such as Figure 9 As shown, in a specific embodiment of this application, the first type of optical fiber module may include: a first component 91 and a second component 92;
[0103] The first component 91 includes: a first optical fiber 911, a second optical fiber 912, a third optical fiber 913, a fourth optical fiber 914, and a first PBS crystal 910;
[0104] The ports of the first optical fiber, the second optical fiber, the third optical fiber, and the fourth optical fiber are respectively connected to the four sides of the first PBS crystal in a clockwise order.
[0105] The angle between the slow axis of the port of the first optical fiber 911 and the slow axis of the first PBS crystal is 63.5°.
[0106] The angle between the slow axis of the port of the second optical fiber 912 and the slow axis of the first PBS crystal is 90°.
[0107] The angle between the slow axis of the port of the third optical fiber 913 and the fourth optical fiber 914 and the slow axis of the first PBS crystal is 0°.
[0108] The second component 92 includes: a fifth optical fiber 925, a sixth optical fiber 926, a seventh optical fiber 927, an eighth optical fiber 928, and a second PBS crystal 920;
[0109] The ports of the fifth, sixth, seventh, and eighth optical fibers are sequentially connected to the four sides of the second PBS crystal in a clockwise order.
[0110] The angle between the slow axis of the ports of the fifth, sixth, seventh, and eighth optical fibers and the slow axis of the second PBS crystal is 0°.
[0111] The other end of the sixth optical fiber 926 is connected to the other end of the first optical fiber 911; the other end of the seventh optical fiber 927 is connected to the other end of the fourth optical fiber 914.
[0112] Therefore, the fifth optical fiber 925 and the eighth optical fiber 928 in the second component can serve as two input terminals of the first type of optical fiber module, while the second optical fiber 912 and the third optical fiber 913 in the first component can serve as two output terminals of the first type of optical fiber module.
[0113] For example, as an example, in a specific embodiment of this application, when the fifth optical fiber 925 receives a superposition of the first quantum state H and the second quantum state V, and the first quantum state H travels along the fast axis and the second quantum state V travels along the slow axis, since the angle between the slow axis of the port of the fifth optical fiber 925 and the slow axis of the second PBS crystal 920 is 0°, the second quantum state V will be transmitted through the second PBS crystal 920 into the slow axis of the port of the seventh optical fiber 927, and transmitted to the fourth optical fiber 914 via the seventh optical fiber 927, while the first quantum state H will be reflected into the slow axis of the port of the sixth optical fiber 926, and transmitted to the first optical fiber 911 via the sixth optical fiber 926.
[0114] like Figure 10As shown, since the angle between the slow axis of the port of the first fiber 911 and the slow axis of the first PBS crystal 910 is 63.5°, a 1:2 splitting ratio can be achieved. The slow axes of the ports of the third fiber 913 and the fourth fiber 914 are aligned with the slow axis of the first PBS crystal 910. Therefore, when linearly polarized light (i.e., the first quantum state H) is input through the slow axis of the port of the first fiber 911, 1 / 3 of the polarized light (i.e., 1 / 3 H quantum state) will be transmitted through the first PBS crystal 910 and enter the slow axis of the port of the third fiber 913, and 2 / 3 of the polarized light (i.e., 2 / 3 H quantum state) will be reflected into the slow axis of the port of the second fiber 912. When linearly polarized light (i.e., the second quantum state V) is input through the fast axis of the port of the fourth fiber 914, it will be completely reflected into the fast axis of the port of the third fiber 913, perpendicular to 1 / 3 of the polarized light on the slow axis. Therefore, a 2 / 3H quantum state can be output from the second fiber 912, and a 1 / 3H+V quantum state can be output from the third fiber 913.
[0115] Therefore, the effect of the first type of fiber optic module at this time is as follows: Figure 12 As shown.
[0116] Similarly, as an example, in a specific embodiment of this application, when the eighth optical fiber 928 receives a superposition of the first quantum state H and the second quantum state V, and the first quantum state H travels along the fast axis and the second quantum state V travels along the slow axis, since the angle between the slow axis of the port of the eighth optical fiber 928 and the slow axis of the second PBS crystal 920 is 0°, the second quantum state V will be transmitted through the second PBS crystal 920 into the slow axis of the port of the sixth optical fiber 926, and transmitted to the first optical fiber 911 via the sixth optical fiber 926, while the first quantum state H will be reflected into the slow axis of the port of the seventh optical fiber 927, and transmitted to the fourth optical fiber 914 via the seventh optical fiber 927.
[0117] like Figure 11As shown, since the angle between the slow axis of the port of the first fiber 911 and the slow axis of the first PBS crystal 910 is 63.5°, a 1:2 splitting ratio can be achieved. The slow axes of the ports of the third fiber 913 and the fourth fiber 914 are aligned with the slow axis of the first PBS crystal 910. Therefore, when linearly polarized light (i.e., the second quantum state V) is input through the fast axis of the port of the first fiber 911, 2 / 3 of the polarized light (i.e., 2 / 3 V quantum state) will pass through the first PBS crystal 910 and enter the slow axis of the port of the third fiber 913, and 1 / 3 of the polarized light (i.e., 1 / 3 V quantum state) will be reflected into the slow axis of the port of the second fiber 912. When linearly polarized light (i.e., the first quantum state H) is input through the slow axis of the port of the fourth fiber 914, it will all pass through the first PBS crystal 910 and enter the fast axis of the port of the second fiber 912, perpendicular to the 1 / 3 of the polarized light on the slow axis. Therefore, the H+1 / 3V quantum state can be output from the second fiber 912, and the 2 / 3 quantum state can be output from the third fiber 913.
[0118] Therefore, the effect of the first type of fiber optic module at this time is as follows: Figure 13 As shown.
[0119] Furthermore, the second type of optical fiber module described above can be implemented in various specific ways in the technical solution of this application. The following will use one specific method as an example to describe the technical solution of this application in detail.
[0120] For example, as an example, such as Figure 14 As shown, in one specific embodiment of this application, the second type of optical fiber module may include: a fourth PBS, a fifth PBS, and a first beam splitter (BS).
[0121] The first output terminal of the fourth PBS is connected to the input terminal of the first beam splitter, and the second output terminal is connected to the second input terminal of the fifth PBS.
[0122] The second output terminal of the first beam splitter is connected to the first input terminal of the fifth PBS; the beam splitting ratio of the first beam splitter is 1:2.
[0123] Therefore, when the input end of the second type of optical fiber module (i.e., the input end of the fourth PBS) receives a superposition of a first quantum state (e.g., a horizontally polarized state H or a |0> state) and a second quantum state (e.g., a vertically polarized state V or a |1> state), the fourth PBS can separate the first and second quantum states and output them to the fifth PBS and the first beam splitter, respectively. For example, the fourth PBS can output the first quantum state H to the first BS and the second quantum state V to the fifth PBS. Since the beam splitting ratio of the first BS is 1:2, the first output end of the first BS will output a 2 / 3H quantum state (i.e., a quantum state with an intensity of 2 / 3 of the original first quantum state H), and the second output end of the first BS will output a 1 / 3H quantum state (i.e., a quantum state with an intensity of 1 / 3 of the original first quantum state H). The fifth PBS can be used as a beam combiner, which can combine the 1 / 3H quantum state received at its first input end and the second quantum state V received at its second input end into a 1 / 3H+V quantum state (i.e., a superposition of the 1 / 3H quantum state and the second quantum state V) for output. At this time, the first output terminal of the first BS and the output terminal of the fifth PBS serve as the two output terminals of the aforementioned second type of optical fiber module, respectively outputting the 2 / 3H quantum state and the 1 / 3H+V quantum state.
[0124] For example, as an example, such as Figure 15 As shown, in one specific embodiment of this application, the second type of optical fiber module may include: a sixth PBS, a seventh PBS, a second BS, and a third BS;
[0125] The first output terminal of the sixth PBS is connected to the input terminal of the second BS, and the second output terminal is connected to the second input terminal of the seventh PBS.
[0126] The second output terminal of the second BS is connected to the input terminal of the third BS;
[0127] The second output terminal of the third BS is connected to the first input terminal of the seventh PBS;
[0128] The beam splitting ratio of the second BS and the third BS is 1:1.
[0129] Therefore, when the input of the aforementioned second type of optical fiber module receives a superposition of a first quantum state (e.g., a horizontally polarized state H or a |0> state) and a second quantum state (e.g., a vertically polarized state V or a |1> state), the sixth PBS can separate the first and second quantum states and output them to the seventh PBS and the second BS respectively. For example, the sixth PBS can output the first quantum state H to the second BS and the second quantum state V to the seventh PBS. Since the beam splitting ratio of the second BS is 1:1, the first output of the second BS will output a 1 / 2H quantum state (i.e., a quantum state with an intensity half the intensity of the original first quantum state H), and the second output of the second BS will also output a 1 / 2H quantum state; the beam splitting ratio of the third BS is also 1:1, so the first output of the third BS will output a 1 / 4H quantum state (i.e., a quantum state with an intensity one-quarter the intensity of the original first quantum state H), and the second output of the third BS will also output a 1 / 4H quantum state. The seventh PBS can be used as a combiner, combining the 1 / 4H quantum state received at its first input and the second quantum state V received at its second input into a 1 / 4H+V quantum state (i.e., a superposition of the 1 / 4H quantum state and the second quantum state V). At this point, the first output of the second BS and the output of the seventh PBS serve as the two outputs of the aforementioned second type of optical fiber module, outputting the 1 / 2H quantum state and the 1 / 4H+V quantum state, respectively.
[0130] As can be seen from the specific structure and function described above, the computing component in the above specific embodiment can realize the function of an optical quantum gate (e.g., the function of an optical quantum controlled-NOT gate with two inputs and two outputs, CNOT). Therefore, the technical solution of this application can utilize the polarization and interference effects of photons to realize the required quantum logic operations in a purely linear optical system, perform corresponding logical control on the quantum gate, and thus perform corresponding variable quantum calculations.
[0131] Furthermore, CNOT gates are generally considered to be the basic two-qubit logic gates required for building universal quantum computers. Therefore, based on the technical solution of this application, more complex quantum computing architectures can be constructed using the aforementioned CNOT gates to perform corresponding quantum logic control or quantum computing. For example, based on the two-input two-output CNOT gates in the specific embodiments described above, four-input four-output or other multi-input multi-output quantum gates can be constructed by stacking or other means.
[0132] Furthermore, while existing technologies have proposed solutions such as optical quantum CNOT gates implemented using only linear optical devices and CNOT gates based on polarization encoding, the CNOT gates in these technologies typically utilize unstable fiber cutting and splicing methods to construct the corresponding optical path. Their polarization splitting ratio control and stability are significantly affected by process stability and the testing environment.
[0133] In the technical solution of this application, since all the computing components use fiber optic modules, some polarization beam splitter (PPBS) elements can be replaced by all-fiber components, such as a combination of special ratio fiber beam splitter (non-polarization dependent) and fiber polarization beam splitter. This allows for the realization of all-fiber quantum gate optical paths in the variable quantum computing process, while maintaining the stability of its operating environment and the robustness of its manufacturing process.
[0134] Furthermore, the technical solution of this application further verifies the feasibility of the all-fiber quantum logic platform and demonstrates its potential in terms of integration, stability, and high-fidelity quantum computing. Compared with existing free-space systems, the all-fiber solution in this application is easier to scale and modularize, which is of great significance for promoting practical quantum computing and quantum communication. The technical solution of this application is not only another breakthrough in optical quantum logic gate systems, but also provides a solid foundation and a clear development direction for subsequent large-scale quantum information processing using fiber optic technology.
[0135] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0136] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A quantum variable quantum computing device, characterized in that, The device includes: a state preparation component, a computing component, and a measurement and detection component; The quantum state preparation component is used to adjust the preparation parameters for preparing quantum states according to the adjustment command; receive the light beam input from the light source, prepare the corresponding quantum state according to the received light beam, and transmit the prepared quantum state to the computing component; The computing component is used to perform quantum logic calculations on the received quantum state and transmit the calculated quantum state to the measurement and detection component. The measurement and detection component is used to prepare the required measurement base, measure the quantum state output by the computing component using the measurement base, and output the measurement result; and calculate the loss function based on the measurement result and the expected result. When the loss function is greater than a preset threshold, an adjustment command is output to the state preparation component based on the value of the loss function. The computing component is an all-fiber component; the computing component includes: a first fiber optic module, a second fiber optic module, and a third fiber optic module; The input end of the first optical fiber module is connected to the output end of the state preparation component, the first output end of the first optical fiber module is connected to the second input end of the second optical fiber module, and the second output end of the first optical fiber module is connected to the first input end of the third optical fiber module. The second output terminal of the second optical fiber module is connected to the first input terminal of the measurement and detection component; The first output terminal of the third optical fiber module is connected to the second input terminal of the measurement and detection component; The first optical fiber module is a type 1 optical fiber module; the second and third optical fiber modules are both type 2 optical fiber modules; The first type of optical fiber module is used to output the superposition state of the first quantum state and the second quantum state from one of its output terminals and output the first quantum state from another of its output terminals when it receives the superposition state of the first quantum state and the second quantum state. The intensity of the first quantum state output by the output terminal that outputs the superposition state is half the intensity of the first quantum state output by the other output terminal. The second type of optical fiber module is used to output a superposition state of the first quantum state and the second quantum state from one of its output terminals and output the first quantum state from another of its output terminals when one of its input terminals receives the first quantum state and the other input terminal receives the second quantum state. The intensity of the first quantum state output by the output terminal that outputs the superposition state is half the intensity of the first quantum state output by the other output terminal.
2. The apparatus according to claim 1, characterized in that, The first type of fiber optic module includes: a first polarization beam splitter, a second polarization beam splitter, a third polarization beam splitter, a first partial polarization beam splitter, and a second partial polarization beam splitter; The two output terminals of the first polarization beam splitter are respectively connected to the input terminals of the first partial polarization beam splitter and the second partial polarization beam splitter; The first output terminal of the first partial polarization beam splitter is connected to the first input terminal of the second polarization beam splitter; the second output terminal of the first partial polarization beam splitter is connected to the first input terminal of the third polarization beam splitter. The first output terminal of the second partial polarization beam splitter is connected to the second input terminal of the second partial polarization beam splitter; the second output terminal of the second partial polarization beam splitter is connected to the second input terminal of the third polarization beam splitter.
3. The apparatus according to claim 2, characterized in that: The first polarization beam splitter is a polarization beam splitter with two input terminals and two output terminals; The second and third polarization beamsplitters are polarization beamsplitters with two input terminals and one output terminal.
4. The apparatus according to claim 2 or 3, characterized in that: The first and second partial polarization beamsplitters are partial polarization beamsplitters with one input and two outputs.
5. The apparatus according to claim 1, characterized in that, The first type of optical fiber module includes: a first component and a second component; The first component includes: a first optical fiber, a second optical fiber, a third optical fiber, a fourth optical fiber, and a first polarization beam splitter crystal; The ports of the first optical fiber, the second optical fiber, the third optical fiber, and the fourth optical fiber are respectively connected to the four sides of the first polarization beam splitter crystal in a clockwise order. The angle between the slow axis of the port of the first optical fiber and the slow axis of the first polarization beam splitter crystal is 63.5°. The angle between the slow axis of the second optical fiber port and the slow axis of the first polarization beam splitter crystal is 90°. The angle between the slow axis of the ports of the third and fourth optical fibers and the slow axis of the first polarization beam splitter crystal is 0°. The second component includes: a fifth optical fiber, a sixth optical fiber, a seventh optical fiber, an eighth optical fiber, and a second polarization beam splitter crystal; The ports of the fifth, sixth, seventh, and eighth optical fibers are sequentially connected to the four sides of the second polarization beam splitter crystal in a clockwise order. The angle between the slow axis of the ports of the fifth, sixth, seventh, and eighth optical fibers and the slow axis of the second polarization beam splitter crystal is 0°. The other end of the sixth optical fiber is connected to the other end of the first optical fiber; the other end of the seventh optical fiber is connected to the other end of the fourth optical fiber.
6. The apparatus according to claim 1, characterized in that, The second type of fiber optic module includes: a fourth polarization beam splitter, a fifth polarization beam splitter, and a first beam splitter; The first output terminal of the fourth polarization beam splitter is connected to the input terminal of the first beam splitter, and the second output terminal is connected to the second input terminal of the fifth polarization beam splitter. The second output terminal of the first beam splitter is connected to the first input terminal of the fifth polarization beam splitter; the beam splitting ratio of the first beam splitter is 1:
2.
7. The apparatus according to claim 1, characterized in that, The second type of fiber optic module includes: a sixth polarization beam splitter, a seventh polarization beam splitter, a second beam splitter, and a third beam splitter; The first output terminal of the sixth polarization beam splitter is connected to the input terminal of the second beam splitter, and the second output terminal is connected to the second input terminal of the seventh polarization beam splitter. The second output terminal of the second beam splitter is connected to the input terminal of the third beam splitter; The second output terminal of the third beam splitter is connected to the first input terminal of the seventh polarization beam splitter; The splitting ratio of the second and third beam splitters is 1:
1.
8. The apparatus according to claim 1, characterized in that, The measurement and detection assembly includes: a measurement base module, a detection module, and a control module; The measurement base module is used to prepare the required measurement base and transmit the prepared measurement base to the detection module; The detection module is used to measure the quantum state output by the computing component using the received measurement basis, and output the measurement result; The control module is used to calculate a loss function based on the measurement results and expected results. When the loss function is greater than a preset threshold, it outputs an adjustment command to the state preparation component based on the value of the loss function.
9. The apparatus according to claim 1, characterized in that: The first quantum state is either a horizontally polarized state H or a |0> state; The second quantum state is either a vertically polarized state V or a |1> state.