Quantum cloning and quantum cryptology attack and defense principle teaching device and teaching method
By designing a teaching device for the principles of quantum cloning and quantum cryptography, and using a Mach-Zehnder interferometer to achieve approximate quantum cloning operations, this invention solves the problem of the lack of teaching devices in ordinary physics laboratories, demonstrates the principle of quantum state non-cloning and the security of quantum cryptography, and is suitable for ordinary physics teaching and scientific and technological demonstrations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIUZHANG (JINAN) QUANTUM TECHNOLOGY CO LTD
- Filing Date
- 2024-03-18
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies lack teaching devices that can directly demonstrate the no-cloning principle of quantum states and the security of quantum cryptography under ordinary physics laboratory conditions. Furthermore, the photon stimulated emission method is complex to implement and has high requirements for the pump laser field.
Design a teaching device for quantum cloning and quantum cryptography attack and defense principles, including a module for preparing and measuring arbitrary polarized quantum states, a quantum cloning machine, and a single-photon receiving and analysis optical path module. It uses a Mach-Zehnder interferometer to realize approximate quantum cloning operations and is suitable for various input light sources.
It enables the demonstration of the no-cloning principle of quantum states and the security of quantum cryptography in ordinary physics laboratories, making it suitable for general physics teaching and scientific demonstrations, and possessing good interactivity and adaptability.
Smart Images
Figure CN118172994B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of quantum information and quantum optics, and in particular to a teaching device and method for quantum cloning and quantum cryptography attack and defense principles. Background Technology
[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.
[0003] The no-cloning theorem for quantum states is a fundamental principle guaranteeing the unconditional security of quantum communication. Quantum (approximate) cloning refers to copying a single qubit into multiple copies. The no-cloning theorem states that due to the superposition and entanglement properties of quantum states, it is impossible to completely copy an unknown quantum state to another qubit, thus ensuring that information cannot be leaked or tampered with during quantum communication. Therefore, the application of quantum cloning and the no-cloning theorem is crucial in quantum cryptography. Furthermore, quantum cryptography also involves other technologies such as multi-party quantum key distribution and quantum teleportation. In short, the no-cloning theorem is an important concept in quantum information science, playing a vital role in quantum cryptography. These technologies can be used to achieve unconditionally secure communication and computation, protecting information security and privacy. Currently, there is a lack of demonstration and teaching machines that explain the principles of these important quantum information concepts.
[0004] Photons are the best physical carriers for quantum information transmission. The quantum approximate cloning of single-photon quantum states can be physically achieved using stimulated emission of photons, but this typically relies on nonlinear optics, is complex to implement, requires a high-precision pump laser field, and is difficult to perform asymmetric quantum cloning operations. Therefore, under typical physics laboratory conditions, there is a lack of teaching devices that can directly demonstrate the principle of the non-cloning of quantum states and the security of quantum cryptography. Summary of the Invention
[0005] To address the technical problems existing in the background art, the present invention provides a teaching device and method for quantum cloning and quantum cryptography attack and defense principles. The teaching device designed by the present invention is easy to adjust and is suitable for a variety of different input light sources, and can be applied to general physics teaching, science and technology demonstration and other application fields.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] The first aspect of the present invention provides a teaching device for the principles of quantum cloning and quantum cryptography attack and defense.
[0008] A teaching device for quantum cloning and quantum cryptography attack and defense principles includes: an arbitrary polarization quantum state preparation and measurement module, a quantum cloning machine, and a single-photon receiving and analysis optical path module arranged sequentially according to the optical path direction. The quantum cloning machine includes a quantum entanglement pair and a Mach-Zehnder interferometer. One photon of the quantum entanglement pair enters the Mach-Zehnder interferometer, and the other photon enters the single-photon receiving and analysis optical path module.
[0009] The arbitrary polarization quantum state preparation and measurement module is used to prepare the generated single-photon signal into an arbitrary polarization quantum state and to measure the prepared arbitrary polarization quantum state.
[0010] The quantum cloning machine is used to employ a Mach-Zehnder interferometer to interfere with a single photon generated by the arbitrary polarization quantum state preparation and measurement module with one photon of a quantum entangled pair, and then adjust the beam splitting ratio of the interfering photon to complete the approximate quantum cloning operation of an arbitrary single photon state and measure the quantum state output by the quantum cloning machine.
[0011] The single-photon receiving and analysis optical path module is used to measure the quantum state of the other photon in a quantum entangled pair.
[0012] Furthermore, the arbitrary polarization quantum state preparation and measurement module includes: an arbitrary polarization quantum state preparation module for preparing the generated single-photon signal into an arbitrary polarization quantum state; the arbitrary polarization quantum state preparation module includes: a single-photon source for inputting the single-photon signal; and following the single-photon source are: a first polarization beam splitter, a first half-wave plate, and a first quarter-wave plate arranged sequentially along the optical path.
[0013] Furthermore, the single-photon source may be a semiconductor quantum dot single-photon source, a spontaneous parametric downconversion process prediction single-photon source, or a pseudo-single-photon source with single-photon intensity level achieved through attenuated pulsed laser.
[0014] Furthermore, the arbitrary polarization quantum state preparation and measurement module further includes: a measurement module for measuring the prepared arbitrary polarization quantum state; the measurement module includes a detachable reflector for transmitting the single photon generated by the arbitrary polarization quantum state preparation module into the quantum cloning machine after transmission, and for reflecting the single photon generated by the arbitrary polarization quantum state preparation module into the second quarter-wave plate, the second half-wave plate, the second polarization beam splitter, and the first single photon detector in sequence.
[0015] Furthermore, the Mach-Zehnder interferometer includes: a first unpolarized optical beam splitter, a second unpolarized optical beam splitter, and a phase adjuster, wherein the phase adjuster adjusts the phase of the transmitted optical signal by vertical translation.
[0016] Furthermore, after the single photon generated by the arbitrary polarization quantum state preparation and measurement module and one photon of the entangled photon pair interfere with each other in the first unpolarized optical beam splitter, one light enters the second unpolarized optical beam splitter after passing through the phase adjuster, while the other light directly enters the second unpolarized optical beam splitter, and then interferes with each other in the second unpolarized optical beam splitter.
[0017] Furthermore, after interference occurs in the second unpolarized optical beam splitter, one beam enters the third single-photon detector; the other beam sequentially enters the third quarter-wave plate, the third half-wave plate, the third polarized beam splitter, and the second single-photon detector.
[0018] Furthermore, the single-photon receiving and analysis optical path module includes a fourth quarter-wave plate, a fourth half-wave plate, a fourth polarization beam splitter, and a fourth single-photon detector arranged sequentially along the optical path.
[0019] A second aspect of the present invention provides a teaching method for the principles of quantum cloning and quantum cryptography attack and defense.
[0020] A teaching method for the principles of quantum cloning and quantum cryptography, employing the teaching device for the principles of quantum cloning and quantum cryptography described in the first aspect, includes:
[0021] An arbitrary polarization quantum state preparation and measurement module is used to prepare the generated single-photon signal into an arbitrary polarization quantum state, and the prepared arbitrary polarization quantum state is measured to calculate the first fidelity of the density matrix of the arbitrary polarization quantum state.
[0022] By adjusting the phase modulator in the quantum cloning machine, asymmetric or symmetric quantum cloning operations are performed on any single-photon state. The quantum state output by the quantum cloning machine is measured, and the second fidelity of the density matrix of the quantum state output by the cloning machine is calculated.
[0023] The quantum state of the other photon in the quantum entanglement pair is measured by the single-photon receiving and analysis optical path module, and the third fidelity of the density matrix of the quantum state of the other photon is calculated.
[0024] The relationship between the second and third fidelities and the first fidelity is verified by adjusting the Mach-Zehnder interferometer to verify the quantum state no-cloning inequality.
[0025] Furthermore, quantum key distribution protocols under different cloning conditions are implemented between the quantum cloning machine and the single-photon receiving and analysis optical path module.
[0026] Compared with the prior art, the beneficial effects of the present invention are:
[0027] This invention, through a phase plate adjusted over the entire period, can form an arbitrarily adjustable non-polarization beam splitter, thereby realizing asymmetric quantum cloning operations with arbitrary information allocation. It allows for the measurement of the initial prepared state and the two quantum states output by the quantum cloning machine, enabling analysis of the fidelity relationships between them. This invention is easy to adjust, highly interactive, and suitable for teaching demonstrations. It is also applicable to various input light sources and can be used in fields such as general physics teaching and scientific demonstrations.
[0028] This invention demonstrates the principle of quantum state remote transmission based on entanglement in real-world scenarios through the distribution of entangled photon pairs, which helps to demonstrate the physical properties of quantum entangled states and their measurement methods in the teaching process. Attached Figure Description
[0029] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0030] Figure 1 This is a diagram of the optical path structure of the teaching device for quantum cloning and quantum cryptography attack and defense principles shown in this invention;
[0031] Figure 2 This is a flowchart illustrating the teaching method for the principles of quantum cloning and quantum cryptography attack and defense as shown in this invention;
[0032] Among them, PBS11 is the first polarization beam splitter, HWP11 is the first half-wave plate, QWP11 is the first quarter-wave plate, FM1 is the detachable mirror, HWP12 is the second half-wave plate, QWP12 is the second quarter-wave plate, PBS12 is the second polarization beam splitter, PD12 is the first single-photon detector, EPR1 is the entangled photon pair, NBS21 is the first unpolarized optical beam splitter, NBS22 is the second unpolarized optical beam splitter, S23 is the phase adjuster, PBS21 is the third polarization beam splitter, HWP21 is the third half-wave plate, QWP21 is the third quarter-wave plate, PD21 is the second single-photon detector, PD22 is the third single-photon detector, PBS3 is the fourth polarization beam splitter, HWP3 is the fourth half-wave plate, QWP3 is the fourth quarter-wave plate, and PD3 is the fourth single-photon detector. Detailed Implementation
[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0034] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0036] It should be noted that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and systems according to various embodiments of this disclosure. It should be noted that each block in a flowchart or block diagram may represent a module, segment, or portion of code, which may include one or more executable instructions for implementing the logical functions specified in the various embodiments. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutively represented blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, may be implemented using a dedicated hardware-based system that performs the specified functions or operations, or using a combination of dedicated hardware and computer instructions.
[0037] Example 1
[0038] like Figure 1 As shown, this embodiment provides a teaching device for quantum cloning and quantum cryptography attack and defense principles, used to realize approximate cloning operations on single-photon quantum states and quantum cryptographic security analysis, applicable to fields such as BB84 quantum key distribution security principle demonstration and single-photon quantum state transmission. The teaching device includes: an arbitrary polarization quantum state preparation and measurement module, a quantum cloning machine, and a single-photon receiving and analysis optical path module.
[0039] Specifically, the arbitrary polarization quantum state preparation and measurement module is used by the sender Alice to prepare and measure arbitrary single-bit quantum states;
[0040] The arbitrary polarization quantum state preparation and measurement module includes: an arbitrary polarization quantum state preparation module and a measurement module;
[0041] The arbitrary polarization quantum state preparation module includes: a single photon source, a first polarization beam splitter PBS11, a first half-wave plate HWP11, and a first quarter-wave plate QWP11, wherein the single photon source is used to input a single photon signal.
[0042] The measurement module includes: a detachable reflector FM1, a second half-wave plate HWP12, a second quarter-wave plate QWP12, a second polarization beam splitter PBS12, and a first single-photon detector PD12, for selectively measuring and reconstructing single-photon quantum states.
[0043] Specifically, the quantum cloning machine is used by EVE to perform approximate quantum cloning operations on arbitrary single-photon states;
[0044] The quantum cloning machine includes: an entangled photon pair EPR1, a first unpolarized optical beam splitter NBS21, a second unpolarized optical beam splitter NBS22, a phase modulator S23, a third single-photon detector PD22, a third polarized beam splitter PBS21, a third half-wave plate HWP21, a third quarter-wave plate QWP21, and a second single-photon detector PD21.
[0045] The first unpolarized optical beam splitter NBS21 or the second unpolarized optical beam splitter NBS22 has a polarization-maintaining balanced beam splitter film coated on its beam splitting film to achieve interference of optical signals incident at the two ports. The first unpolarized optical beam splitter NBS21 or the second unpolarized optical beam splitter NBS22 also includes a total reflection surface to convert the two outgoing beams into parallel propagation.
[0046] The phase adjuster S23 can adjust the phase of the transmitted optical signal [0, 2Pi] by translating it up and down;
[0047] The third single-photon detector PD22 is capable of 0 / 1 threshold detection of single photons and generating a prediction signal; and / or
[0048] The third polarization beam splitter PBS21, the third half-wave plate HWP21, the third quarter-wave plate QWP21, and the second single-photon detector PD21 are used to analyze the photon quantum state at their respective ports.
[0049] Specifically, the single-photon receiving and analyzing optical path module is used by Bob to measure the photonic quantum state;
[0050] The single-photon receiving and analysis optical path module includes: a fourth polarization beam splitter PBS3, a fourth half-wave plate HWP3, a fourth quarter-wave plate QWP3, and a fourth single-photon detector PD3, used to analyze the photon quantum state at the port.
[0051] More specifically, a single-photon source can be a semiconductor quantum dot single-photon source, a spontaneous parametric downconversion process prediction single-photon source, or a pseudo-single-photon source with single-photon intensity level achieved through attenuated pulsed laser.
[0052] Example 2
[0053] This embodiment provides a teaching method for the principles of quantum cloning and quantum cryptography attack and defense.
[0054] like Figure 2 As shown, a teaching method for the principles of quantum cloning and quantum cryptography attack and defense, using the teaching device for the principles of quantum cloning and quantum cryptography attack and defense described in Example 1, includes:
[0055] S01: The first polarization beam splitter PBS11 can be used to polarize the input signal and prepare a quantum state with H polarization. Using the first half-wave plate HWP11 and the first quarter-wave plate QWP11, an arbitrary quantum state |ψ>=a|H>+b|V> can be prepared from the single-photon state. Due to imperfections in the experimental operation, the density matrix of the initially prepared actual single-photon state can be measured by adding a detachable mirror FM1, a second half-wave plate HWP12, a second quarter-wave plate QWP12, a second polarization beam splitter PBS12, and a first single-photon detector PD12, thereby obtaining the fidelity of the initial state preparation.
[0056] S02: EVE achieves asymmetric or symmetric quantum cloning operations by adjusting the phase modulator S23. The quantum cloning machine includes an entangled photon pair EPR1, whose quantum state is... The system comprises a first unpolarized optical beamsplitter NBS21, a second unpolarized optical beamsplitter NBS22, a phase adjuster S23, a third single-photon detector PD22, a third polarized beamsplitter PBS21, a third half-wave plate HWP21, a third quarter-wave plate QWP21, and a second single-photon detector PD21. The first unpolarized optical beamsplitter NBS21, the second unpolarized optical beamsplitter NBS22, and the phase adjuster S23 together form an adjustable beam-splitting ratio Mach-Zehnder interferometer, capable of achieving a reflection ratio of R and a transmission ratio of T.
[0057] S03: EVE and Bob measure the single-photon quantum state at their respective ports. In the above embodiment, assuming all components are ideal, by adjusting the phase modulator S23, when R = 1 / 3, EVE and Bob obtain the same quantum state. By using the third polarization beam splitter PBS21, the third half-wave plate HWP21, the third quarter-wave plate QWP21, the second single-photon detector PD21, and the fourth polarization beam splitter PBS3, the fourth half-wave plate HWP3, the fourth quarter-wave plate QWP3, and the fourth single-photon detector PD3, density matrix 1 and density matrix 2 can be measured respectively, satisfying the following fidelity:
[0058]
[0059] Where F2 represents the fidelity of density matrix 1 and F3 represents the fidelity of density matrix 2.
[0060] This enables symmetric cloning.
[0061] S04: Verify the fidelity of the two output quantum states relative to the initial state and their relationship. By adjusting different proportions of reflection R, the no-cloning inequality of quantum states can be verified.
[0062]
[0063] S05: Alice and Bob can conduct quantum key distribution protocols under different cloning conditions. This can be done by conducting code generation tests between Alice and Bob under different reflection ratios R, such as verifying the code generation test using the BB84 protocol.
[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A teaching device for the principles of quantum cloning and quantum cryptography attack and defense, characterized in that, include: The arbitrary polarization quantum state preparation and measurement module, the quantum cloning machine, and the single-photon receiving and analysis optical path module are arranged sequentially according to the optical path direction. The quantum cloning machine includes a quantum entanglement pair and a Mach-Zehnder interferometer. One photon of the quantum entanglement pair enters the Mach-Zehnder interferometer, and the other photon enters the single-photon receiving and analysis optical path module. The arbitrary polarization quantum state preparation and measurement module is used to prepare the generated single-photon signal into an arbitrary polarization quantum state and to measure the prepared arbitrary polarization quantum state. The quantum cloning machine is used to employ a Mach-Zehnder interferometer to interfere with a single photon generated by the arbitrary polarization quantum state preparation and measurement module with one photon of a quantum entangled pair, and then adjust the beam splitting ratio of the interfering photon to complete the approximate quantum cloning operation of an arbitrary single photon state and measure the quantum state output by the quantum cloning machine. The single-photon receiving and analysis optical path module is used to measure the quantum state of the other photon in a quantum entangled pair.
2. The teaching device for quantum cloning and quantum cryptography attack and defense principles according to claim 1, characterized in that, The arbitrary polarization quantum state preparation and measurement module includes: an arbitrary polarization quantum state preparation module for preparing the generated single-photon signal into an arbitrary polarization quantum state; the arbitrary polarization quantum state preparation module includes: a single-photon source for inputting the single-photon signal; and following the single-photon source are: a first polarization beam splitter, a first half-wave plate, and a first quarter-wave plate arranged sequentially along the optical path.
3. The teaching device for quantum cloning and quantum cryptography attack and defense principles according to claim 2, characterized in that, The single-photon source is a semiconductor quantum dot single-photon source, a spontaneous parametric downconversion process prediction single-photon source, or a pseudo-single-photon source with single-photon intensity level achieved through attenuated pulsed laser.
4. The teaching device for quantum cloning and quantum cryptography attack and defense principles according to claim 1, characterized in that, The arbitrary polarization quantum state preparation and measurement module further includes: a measurement module for measuring the prepared arbitrary polarization quantum state; the measurement module includes a detachable reflector for transmitting the single photon generated by the arbitrary polarization quantum state preparation module into the quantum cloning machine after transmission, and for reflecting the single photon generated by the arbitrary polarization quantum state preparation module into the second quarter-wave plate, the second half-wave plate, the second polarization beam splitter and the first single photon detector in sequence.
5. The teaching device for quantum cloning and quantum cryptography attack and defense principles according to claim 1, characterized in that, The Mach-Zehnder interferometer includes: a first unpolarized optical beam splitter, a second unpolarized optical beam splitter, and a phase adjuster, wherein the phase adjuster adjusts the phase of the transmitted optical signal by translating it up and down.
6. The teaching device for quantum cloning and quantum cryptography attack and defense principles according to claim 5, characterized in that, After the single photon generated by the arbitrary polarization quantum state preparation and measurement module and one photon of the entangled photon pair interfere with each other in the first unpolarized optical beam splitter, one photon enters the second unpolarized optical beam splitter after passing through the phase adjuster, and the other photon directly enters the second unpolarized optical beam splitter, and then interferes with each other in the second unpolarized optical beam splitter.
7. The teaching device for quantum cloning and quantum cryptography attack and defense principles according to claim 6, characterized in that, After interference occurs at the second unpolarized optical beam splitter, one beam enters the third single-photon detector; the other beam sequentially enters the third quarter-wave plate, the third half-wave plate, the third polarized beam splitter, and the second single-photon detector.
8. The teaching device for quantum cloning and quantum cryptography attack and defense principles according to any one of claims 1-7, characterized in that, The single-photon receiving and analysis optical path module includes a fourth quarter-wave plate, a fourth half-wave plate, a fourth polarization beam splitter, and a fourth single-photon detector arranged sequentially along the optical path.
9. A teaching method for the principles of quantum cloning and quantum cryptography attack and defense, characterized in that, The teaching device for quantum cloning and quantum cryptography attack and defense principles according to any one of claims 1-8 includes: An arbitrary polarization quantum state preparation and measurement module is used to prepare the generated single-photon signal into an arbitrary polarization quantum state, and the prepared arbitrary polarization quantum state is measured to calculate the first fidelity of the density matrix of the arbitrary polarization quantum state. By adjusting the phase modulator in the quantum cloning machine, asymmetric or symmetric quantum cloning operations are performed on any single-photon state. The quantum state output by the quantum cloning machine is measured, and the second fidelity of the density matrix of the quantum state output by the cloning machine is calculated. The quantum state of the other photon in the quantum entanglement pair is measured by the single-photon receiving and analysis optical path module, and the third fidelity of the density matrix of the quantum state of the other photon is calculated. The relationship between the second and third fidelities and the first fidelity is verified by adjusting the Mach-Zehnder interferometer to verify the quantum state no-cloning inequality.
10. The teaching method for quantum cloning and quantum cryptography attack and defense principles according to claim 9, characterized in that, A quantum key distribution protocol under different cloning conditions is implemented between the quantum cloning machine and the single-photon receiving and analysis optical path module.