A dynamic quantum state routing device based on a tunable topological invariant and a control method thereof

Abstract

The application discloses a kind of based on the dynamic quantum state routing device of tunable topological Chen number and control method thereof.The device includes topological photonic crystal routing core (containing multiple waveguide branches are connected to each output port), Chen number control array (independent control local topological Chen number of each branch), routing control module, input / output port, routing state monitoring module and topological stability feedback module.Local topological Chen number is realized continuous adjustment by control projection angle (,, );Chen number-port mapping table establishes the corresponding relationship with the first output port;topological stability feedback module ensures topological protection continuity according to criterion in routing switching;Routing state monitoring module verifies routing state by local Berry curvature measurement.The application realizes the dynamic reconfigurable topological protection routing of quantum state between the first output port, switching time, fidelity, and is suitable for quantum communication network and quantum internet and the like scene.

Description

Technical Field

[0001] This invention relates to the fields of quantum information transmission technology and topological photonics, specifically to a dynamic quantum state routing device and its control method based on a tunable topological Chern number. This invention can be applied to quantum communication networks, the quantum internet, distributed quantum computing, multi-user quantum key distribution, quantum network switching nodes, and other fields, and is particularly suitable for quantum network node applications that require dynamic selection and switching of quantum state transmission paths among multiple output ports. Background Technology

[0002] Quantum routers are core devices in quantum networks, responsible for guiding quantum states from input ports to target output ports, enabling directional transmission of quantum information in complex networks. In recent years, dynamically reconfigurable topology routing has been theoretically verified in nonlinear photonic systems, and local topological properties can be controlled in real time through spatial mode optical pumping. Progress has also been made in the research of multifunctional topology routing based on phase modulation in circuit-based QED systems. However, existing quantum routing technologies still face the following fundamental challenges: (i) Fixed routing paths, lacking dynamic reconfigurability In existing topological photonic routing schemes, the routing path is determined by the static topology of the device and is fixed once manufactured. Although dynamic reconfigurable topological routing has been proposed in theory, existing schemes rely on spatial mode control of optical pumping and lack chip-level integration schemes based on electrical control, making it difficult to achieve real-time switching and on-demand configuration of quantum state routing paths. (ii) There is a lack of direct mapping between Chen number control and routing switching. In existing topological photonic devices, the topological Chern number The existence and propagation direction of the boundary state are determined. Although the "Chern valve" mechanism has been proposed to control the Chern number of the surface states of topological insulators, a direct mapping relationship between the topological Chern number and the routing output port has not yet been established, making it impossible to achieve precise routing of quantum states among multiple output ports by controlling the Chern number. (iii) Multi-port routing lacks programmable architecture Existing sub-routing solutions are mostly limited to simple switching between two or three ports, lacking support for large-scale multi-port operations. A programmable architecture for dynamic routing. In multi-user quantum networks, quantum states need to be flexibly switched between multiple output ports, which existing solutions cannot meet. (iv) Topology protection continuity cannot be guaranteed during route switching During dynamic route switching, changes in the Chern number can lead to the failure of topology protection during the transient phase transition of the topology, and the quantum state is affected by decoherence at the moment of switching. Existing schemes lack a mechanism to maintain the continuity of topology protection during route switching. (v) Lack of routing state verification based on topology invariants In existing sub-routing schemes, the confirmation of routing status relies on optical measurements or quantum state tomography, lacking real-time routing status verification methods based on topological invariants, and cannot immediately confirm whether the quantum state has been successfully routed to the target port after a route switch. To address the above problems, this invention provides a dynamic quantum state routing device and its control method based on tunable topological Chern number. Summary of the Invention

[0003] (a) Purpose of the invention This invention aims to address the technical problems in existing quantum routing technologies, such as fixed routing paths lacking dynamic reconfigurability, lack of direct mapping between Chern number adjustment and route switching, lack of programmable architecture for multi-port routing, inability to guarantee topology protection continuity during route switching, and lack of route state verification based on topology invariants. It provides a dynamic quantum state routing device and its control method based on tunable topology Chern number, which realizes dynamic, programmable, and topology-protected routing of quantum states among multiple output ports by adjusting the topology Chern number. (II) Technical Solution This invention provides a dynamic quantum state routing device based on tunable topological Chern number, characterized in that it comprises: A topological photonic crystal routing core is disposed on a semiconductor substrate and includes multiple topological photonic crystal waveguide branches, each branch being connected to a corresponding output port. The routing core has an adjustable topological Chern number. A Chern number control array, connected to the topological photonic crystal routing core, contains multiple independently controllable control units. Each control unit independently controls the local topological Chern number of the corresponding region or branch through an external field (electric field, magnetic field, optical field or stress field). A routing control module, connected to the Chen number control array, is used to determine the target output port and generate the corresponding Chen number control scheme according to the routing table or real-time control instructions. An input port is connected to the input of the topological photonic crystal routing core to receive the quantum state to be routed; Multiple output ports are connected to the ends of each waveguide branch of the topological photonic crystal routing core for outputting the quantum state after routing; A routing status monitoring module is connected to the topological photonic crystal routing core and is used to verify the current routing status in real time by measuring the local Berry curvature or edge state dispersion relationship. A topology stability feedback module is connected to the routing status monitoring module and the Chen number control array. It is used to adjust the Chen number control parameters in real time according to the topology stability criteria during the routing switch to ensure the continuity of topology protection. Topological photonic crystal routing core structure The topological photonic crystal routing core includes: A topological photonic crystal region is composed of two or more materials with different dielectric constants arranged periodically, and has a tunable non-zero topological Chern number; An input waveguide is connected to the input end of the topological photonic crystal region; Multiple output waveguide branches radiate outward from the topological photonic crystal region, and each branch is connected to a corresponding output port; Multiple control electrodes or control windows are set in the root region of each output waveguide branch to independently control the local topological Chern number of each branch. Physical mechanism of tunable topological Chern number Definition of topological Chern number: The topological Chem number of the core of the topological photonic crystal routing Defined as: in For Berry curvature, It is a closed surface within the Brillouin zone. The topological Chern number takes integer values, and a non-zero Chern number is used. Provides topology protection. Definition of projection angle: The projection angle Defined as: The relationship between Chen Shu and the projection angle: The local topological Chem number By adjusting the projection angle of the corresponding area Achieve continuous adjustment: in For the maximum topological Chern number, This is the theoretically optimal projection angle. Chen Shu - Port Mapping Relationship: The routing control module pre-stores a mapping table between the output values ​​and the output ports. The target topology value corresponding to each output port satisfy: in Based on the Chen number, The step size is set to the quantumized Chern number. This is achieved by adjusting the local topology Chern number of the routing core to... The quantum state is routed to the first One output port. Routing switching principle: When a quantum state enters the routing core of a topological photonic crystal from the input port, its propagation direction is determined by the topological Chern number distribution of the routing core. The quantum state propagates along the topological boundary states, the position and orientation of which are determined by the local topological Chern number. Decide: when At that time, the boundary state along the first Propagation through one output waveguide branch; when When the boundary state does not enter the branch or decays in the branch. By adjusting the local topological Chern number at the root of each output waveguide branch, the quantum state is selectively directed to the target output port. Routing switching protocol: The dynamic quantum state routing device supports the following routing switching protocols: (1) Direct switching: Change the local topology of the target output port from Switch directly to Switching time ; (2) Adiabatic switching: During the switching process, the system is kept in the ground state of the topological nontrivial phase to avoid excitation during the topological phase transition process; (3) Cascade switching: The local topology of multiple output ports is switched sequentially to realize the sequential routing of quantum states between multiple ports. Topology stability criterion (during route switching): During route switching, the topology stability feedback module continuously monitors the rate of change of the projection angle. The following criteria are used to determine whether topology protection is continuous during the routing process: in For the first Topology loss rate of each control region The rate of change of the projection angle. For local topological Chern numbers, The coefficient of recovery, is Planck's constant. When the criteria are met, topology protection remains effective during route switching; when the criteria are not met, feedback adjustment is triggered to slow down the switching speed or optimize the control path. Route status verification: The routing status monitoring module verifies the current routing status in the following ways: (1) Berry curvature measurement: Measure the local Berry curvature at the root of each output waveguide branch and calculate the current local topological Chern number. ; (2) Edge state dispersion measurement: Measure the dispersion relationship of the edge states in each output waveguide branch to confirm the existence and propagation direction of the topological boundary states; (3) Routing state determination: when At that time, it was confirmed that the quantum state had been successfully routed to the first... One output port. Multi-port programmable routing: The dynamic quantum state routing device supports One output port The local topology for each output port can be configured independently, supporting the following routing modes: Unicast mode: Quantum state routing to a single specified output port; Multicast mode: Quantum states are simultaneously routed to multiple specified output ports; Broadcast mode: The quantum state is simultaneously routed to all output ports; Dynamic scanning mode: The quantum state cycles through the output ports in a preset order. Routing performance parameters: Routing switch time: ; Number of output ports: ; Router fidelity: ; Inter-channel crosstalk: ; Operating wavelength: (C-band). (III) Beneficial Effects Dynamically reconfigurable routing: Real-time switching and on-demand configuration of quantum state routing paths are achieved by adjusting the local topology Chern number, without changing the physical structure of the device; Chern number-port direct mapping: A direct mapping relationship is established between the topological Chern number and the output port, and the precise guidance of the quantum state among multiple output ports is achieved by precisely controlling the Chern number; Multi-port programmable architecture: Supports Independent programming configuration for each output port, supporting multiple routing modes such as unicast, multicast, broadcast, and dynamic scanning; Topology protection continuity: During route handover, topology stability criteria are used for real-time monitoring and feedback adjustments to ensure the continuity of topology protection and avoid decoherence during handover transients; Real-time verification of routing status: The routing status is verified in real time by Berry curvature and edge state dispersion measurements, without relying on external quantum state tomography; Chip-level integration: Based on a topological photonic crystal platform, it is compatible with existing silicon photonic processes and is suitable for large-scale integration. Attached Figure Description

[0004] Figure 1 This is a schematic diagram of the overall structure of a dynamic quantum state routing device based on a tunable topological Chern number, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of the topological photonic crystal routing core and Chern number control array provided in an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the principle of Chen number-port mapping and route switching provided in an embodiment of the present invention. Figure 4 The flowchart of dynamic quantum state routing control provided in the embodiments of the present invention. Detailed Implementation

[0005] Example 1: An eight-port quantum state routing device based on tunable topological Chern number Step 1: Fabrication of the topological photonic crystal routing core A topological photonic crystal routing core was fabricated on an SOI substrate. A honeycomb lattice topological photonic crystal structure was fabricated using electron beam lithography and ICP etching, with a lattice constant of [missing information]. Operating wavelength The routing core contains one input port and eight output ports, with each output waveguide branch radiating outward from the routing core. Step 2: Configure the Chern number control array Gate electrodes are integrated in the root region of each output waveguide branch, and a gate voltage is applied ( Independently adjust the local projection angle of each branch. Thus regulating the local topological Chern number. Chen Shu's control precision Response time of regulation Projection angle Defined as ,satisfy . Step 3: Configure the Chen number-port mapping table The routing control module pre-stores a mapping table between Chen values ​​and output ports. The target topology Chen values ​​corresponding to the 8 output ports are as follows: , , , , (Step length) ). Step 4: Quantum State Routing The input port receives the quantum state to be routed. The routing control module determines the target output port (e.g., port 3) based on the routing table and generates the corresponding Chern number adjustment scheme: adjusting the local topology Chern number of the region corresponding to port 3 to... The local topology number of other ports is adjusted to a trivial value. . Step 5: Routing handover and topology protection continuity monitoring During route switching, the topology stability feedback module continuously monitors the rate of change of the projection angle. According to the criteria: Ensure topology protection continuity. Actual switching time measurement. . Step 6: Route Status Verification The routing status monitoring module verifies the routing status by measuring the local Berry curvature, confirming that the quantum state has successfully routed to port 3. Routing fidelity. Crosstalk between channels . Example 2: Dynamic Scanning Route Mode Step 1: Configure dynamic scanning mode The routing device is configured to a dynamic scanning mode, where the quantum state cycles through eight output ports in a preset order, and the dwell time of each port is programmable. – ). Step 2: Loop route switching The routing control module sequentially switches the local topology number of each port to the target value according to a preset order: Port 1 Port 2 Port 3 Port 8 Port 1 loops. Switching time per step. Topology protection remains continuous during the handover process. Step 3: Continuous monitoring of route status The routing status monitoring module monitors the local Berry curvature of each port in real time to confirm that the quantum state is transmitted cyclically between the ports in a preset order. Example 3: Multicast Routing Mode Step 1: Configure multicast mode Configure the routing device to multicast mode, and the quantum state needs to be routed to ports 2, 5, and 7 simultaneously. Step 2: Simultaneous control of multiple ports The routing control module simultaneously adjusts the local topology curves corresponding to ports 2, 5, and 7 to their respective target values, while adjusting the local topology curves of other ports to their common values. . Step 3: Multicast transmission verification The quantum state is simultaneously output from all three output ports. The routing status monitoring module verifies that the local Berry curvature of all three ports is within the target value, confirming successful multicast routing. Terminology Explanation

[0006] Terminology Meaning Tunable topological Chern numbers allow for continuous modulation of the local topological Chern number C of a topological photonic crystal by external fields (electric, magnetic, optical, or stress fields). The Chern number-port mapping establishes a correspondence between the Chern number and the output port in the topology, allowing the quantum state to be directed to the target port by adjusting the Chern number. Local topological Chern number (C_i): The topological Chern number of a specific region or branch within the topological photonic crystal routing core, which can be independently adjusted. Topologically protected propagation modes at the interface between topologically nontrivial and trivial phases in topological boundary states. A Chern number control array is an array composed of multiple independently controllable control units, used to independently control the local topological Chern number of each region. Route status monitoring verifies the current route status in real time by measuring local Berry curvature or edge state dispersion relations. The topology stability feedback is a closed-loop feedback mechanism that adjusts the Chen number control parameters in real time based on topology stability criteria during route switching.

Claims

1. A dynamic quantum state routing device based on tunable topological Chern number, characterized in that, include: A topological photonic crystal routing core is disposed on a semiconductor substrate and includes multiple topological photonic crystal waveguide branches, each branch being connected to a corresponding output port. The routing core has an adjustable topological Chern number. A Chern number control array is connected to the topological photonic crystal routing core and contains multiple independently controllable control units. Each control unit independently controls the local topological Chern number of the corresponding region or branch through an external field. A routing control module, connected to the Chen number control array, is used to determine the target output port and generate the corresponding Chen number control scheme according to the routing table or real-time control instructions. An input port is connected to the input of the topological photonic crystal routing core to receive the quantum state to be routed; Multiple output ports are connected to the ends of each waveguide branch of the topological photonic crystal routing core for outputting the quantum state after routing; A routing status monitoring module is connected to the topological photonic crystal routing core and is used to verify the current routing status in real time by measuring the local Berry curvature or edge state dispersion relationship. A topology stability feedback module is connected to the routing status monitoring module and the Chen number control array, and is used to adjust the Chen number control parameters in real time according to the topology stability criteria during the routing switch.

2. The apparatus according to claim 1, characterized in that: The topological Chem number Defined as ,in For Berry curvature, A closed surface in the Brillouin zone; the local topological Chern number By adjusting the projection angle of the corresponding area To achieve continuous adjustment, ,in , .

3. The apparatus according to claim 1, characterized in that: The routing control module pre-stores a mapping table between the output value and the output port. The target topology value corresponding to each output port satisfy By adjusting the local topological Chern number to Routing the quantum state to the first One output port.

4. The apparatus according to claim 1, characterized in that: The dynamic quantum state routing device supports One output port Each output port's local topology can be independently programmed and configured, supporting at least one routing mode among unicast, multicast, broadcast, and dynamic scanning modes.

5. The apparatus according to claim 1, characterized in that: The topology stability feedback module performs a judgment based on criteria during route switching. To determine whether topology protection is continuous, among which... For the first Topology loss rate of each control region The rate of change of the projection angle. For local topological Chern numbers, The coefficient of recovery, It is Planck's constant; feedback adjustment is triggered when the criterion is not met.

6. The apparatus according to claim 1, characterized in that: The routing status monitoring module calculates the current local topological Chern number by measuring the local Berry curvature at the root of each output waveguide branch. ,when It was confirmed that the quantum state had been successfully routed to the first... One output port.

7. The apparatus according to claim 1, characterized in that: The control response time of the Chern control array Chen Shu's control precision Each control unit independently controls the local topological Chern number through at least one of the following methods: electric field, magnetic field, optical field, or stress field.

8. The apparatus according to claim 1, characterized in that: The topological photonic crystal routing core is composed of a periodic arrangement of two or more materials with different dielectric constants, and has a non-zero topological Chern number. The multiple output waveguide branches radiate outward from the routing core, and each branch root region is provided with an independent control electrode or control window.

9. A dynamic quantum state routing method based on tunable topological Chern number, characterized in that, Includes the following steps: (1) The target output port is determined by the routing control module based on the routing table or real-time control instructions; (2) Determine the target topology Chen value corresponding to the target output port based on the Chen number-port mapping table. ; (3) Adjust the local topology Chern number of the region corresponding to the target output port to the specified value using a Chern number control array. The local topological Chern number in other regions is adjusted to a trivial value; (4) The quantum state enters the topological photonic crystal routing core from the input port and propagates along the topological boundary state to the target output port; (5) During the route switching process, the topology stability feedback module continuously monitors the rate of change of the projection angle. Ensure topology protection continuity based on topology stability criteria; (6) Measure the local Berry curvature through the routing status monitoring module to verify whether the quantum state is successfully routed to the target output port.

10. The method according to claim 9, characterized in that: The quantum state described in step (4) propagates along the topological boundary state, and the position and orientation of the boundary state are determined by the local topological Chern number. Decision: When Time boundary state along the first Each output waveguide branch propagates; the routing switching time Router fidelity Crosstalk between channels .

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