A decentralized quantum walk system

Abstract

The present application discloses a decentralized quantum walking system, including a first quantum walking network, a first optical delay array, a first optical switch, a quantum optical channel, a second optical switch, a second optical delay array, and a second quantum walking network. The present application realizes a decentralized quantum walking system and a decentralized quantum walking method through encoding of quantum walking intermediate states, remote quantum channel transmission and decoding, and completes part of the quantum walking process in the first quantum walking network and the second quantum walking network respectively, and the two quantum walking networks jointly configure the walking process of the quantum walking, realizing remote control and coordination.

Description

Technical Field

[0001] The present application belongs to the field of quantum information technology, and specifically, relates to a decentralized quantum walk system. Background Art

[0002] As the counterpart of classical random walk in the quantum world, quantum walk, under the influence of quantum coherence and entanglement, can enable the walker to traverse all positions at a faster speed, and can be applied to implement various algorithms and accelerate the solution of various problems. In addition, as an effective model for describing the dynamic evolution of microscopic particles, quantum walk can also be used as a universal platform to realize all unitary evolutions, realize quantum state preparation, quantum logic gate operation and quantum measurement, and thus realize all key steps in information processing.

[0003] The existing quantum walk implementation method is mainly based on an optical system composed of polarization-encoded spatial optical devices. For example, in the Chinese invention patent application "A quantum random number generation system and method based on optical quantum walk" (application number: CN202311122169.X), a quantum walk system is constructed using spatial optical devices such as polarization beam splitters, half-wave plates, fiber couplers, and beam shifters. Then, when the number of quantum walks increases, the number of required spatial optical devices increases linearly, the crystal thickness of the beam shifter becomes larger and larger, the total volume of the system becomes huge, and the installation accuracy of various spatial optical devices also affects the stability of quantum walks, which is not conducive to practical application and industrialization. In order to achieve large-scale and stable quantum random walks and promote their industrialization, in recent years, some researchers have proposed to use integrated photonic technology to prepare quantum random walk chips. Since the volume of on-chip optical devices is much smaller than that of spatial optical devices, and the arrangement is more compact, the optical path is relatively stable, which can improve the stability of quantum walks and reduce the volume of the system. Integrated photonic chips are often produced and processed using existing CMOS process production lines, and the chip size is limited by the exposure field of the lithography machine. In addition, due to the problem of the optical waveguide's ability to bind light, its size is several orders of magnitude larger than that of electronic devices. Therefore, the number of devices integrated on a single chip of existing photonic integrated chips is limited (compared to the hundreds of millions of devices on electronic chips), and it is impossible to achieve a larger-scale quantum walk chip. In addition, in some application fields that require remote control and remote collaborative work, it is necessary to call quantum walk modules located in two physical space locations to jointly complete the quantum walk process in order to realize specific algorithms and functions. The current quantum walk systems can only complete quantum walks locally, and then transmit the results to the demander through classical data channels, and cannot achieve end-to-end remote quantum control and collaboration. Summary of the invention

[0004] In order to solve the above problems, this application provides a decentralized quantum walk system, and its specific solution is as follows:

[0005] The present application discloses a decentralized quantum walk system, including a first quantum walk network, a first optical delay array, a first optical switch, a quantum optical channel, a second optical switch, a second optical delay array, and a second quantum walk network;

[0006] The first quantum walking network includes two initial state input terminals, a photonic network composed of N-level path selection arrays cascaded, and 2 N intermediate state output ports, which are used to input the initial state photons of quantum walk, complete N quantum walk operations, and output the intermediate state photons after N quantum walks, where N is an integer greater than 1;

[0007] The first optical delay array includes 2 N A single photon delay unit, and 2 N The intermediate state output ports are connected one by one to delay the intermediate state photons output by each intermediate state output port by different time periods;

[0008] The first optical switch includes 2 N Input terminal and output terminal, connect 2 N A primary photon delay unit and a quantum optical channel are used to merge the delayed intermediate state photons into the same path and transmit them to the second optical switch via the quantum optical channel;

[0009] The second optical switch includes an input terminal and 2 N output ends, respectively connected to the quantum optical channel and the second optical delay array, for sending the intermediate state photons transmitted by the quantum optical channel to the second optical delay array in sequence according to a preset timing;

[0010] The second delay array includes 2 N A secondary photon delay unit, and the 2 N The output ends are connected one by one to the second optical switch. N The intermediate state photons output from each output port are delayed for different times, and the total delay of each intermediate state photon is equal;

[0011] The second quantum walking network includes 2 N intermediate state input terminals, a photonic network consisting of a cascade of M-level path selection arrays, and (2 N +2M) quantum walking state output terminals are respectively used to receive intermediate state photons and continue quantum walking operations, to complete M quantum walking operations, and to output photons after (N+M) quantum walks, where M is an integer greater than 0.

[0012] Furthermore, the Nth level path selection array in the first quantum walking network includes 2 N-1The M-th level path selection array in the second quantum walking network includes (2 N-1 +M) path selection units.

[0013] Further, the path selection unit includes a phase modulator and a 50:50 beam splitter, and the 50:50 beam splitter includes an input upper end, an input lower end, an output upper end, and an output lower end;

[0014] The phase modulator is connected to the lower input end of the 50:50 beam splitter and is used to input the photons of the path selection unit to perform the coin tossing operation of the quantum walk. The corresponding coin tossing operator is:

[0015] ;

[0016] in, is the phase value modulated by the phase modulator;

[0017] The 50:50 beam splitter is used to perform a shift operation on the photons input into it in the quantum walk, and the corresponding displacement operator is:

[0018] ,

[0019] Where x represents the path number of the photon, or Indicates the coin state. When the coin state is , the photon travels to Position; when the coin state is , the walker reaches Location.

[0020] Preferably, the first photon delay unit to the second photon delay unit in the first optical delay array N The delay time of each photon delay unit is 0, τ, 2τ...(2 N -1)τ.

[0021] Preferably, the quantum optical channel is a transmission optical fiber, and the first optical switch and the second optical switch are optically connected to the transmission optical fiber by edge coupling or grating coupling. Alternatively, the quantum optical channel is an optical waveguide chip, and the optical waveguide chip includes a planar waveguide or a three-dimensional waveguide, and the first optical switch and the second optical switch are optically connected to the optical waveguide chip by edge coupling or grating coupling.

[0022] Preferably, the first optical switch is composed of a plurality of MZ interferometers cascaded, the MZ interferometer includes two input ends and two output ends, and is used to output photons input from any input end from the same output end. The second optical switch is composed of a plurality of MZ interferometers cascaded, the MZ interferometer includes two input ends and two output ends, and is used to output photons input from one of the input ends from the two output ends respectively at a preset timing.

[0023] Preferably, the first quantum walking network, the first optical delay array, and the first optical switch are integrated on one chip, and the second optical switch, the second optical delay array, and the second quantum walking network are integrated on one optical chip.

[0024] Furthermore, a control module is electrically connected to the first optical switch and the second optical switch, and is used to control the first optical switch and the second optical switch to adjust the photon path; the control module is also electrically connected to the path selection unit, and is used to control each coin tossing operation in the quantum walk.

[0025] In general, the above technical solutions conceived by the present application can achieve the following beneficial effects compared with the prior art:

[0026] The present application provides a decentralized quantum walk system, which includes a first quantum walk network, a first optical delay array, a first optical switch, a quantum optical channel, a second optical switch, a second optical delay array, and a second quantum walk network. In the first quantum walk network, a quantum walk intermediate state represented by a photon path is formed, and then the photons in the intermediate state are encoded by time through the first optical delay array and the first optical switch, merged into an optical signal of the same path and transmitted through the quantum optical channel, and then the optical signal is decoded through the second optical switch and the second optical delay array, and restored to the original quantum walk intermediate state represented by the photon path, and then the quantum walk is continued in the second quantum walk network. Based on the above scheme, it can be seen that the present application realizes a decentralized quantum walk system and a decentralized quantum walk method through the encoding, remote quantum channel transmission and decoding of the quantum walk intermediate state, and completes part of the quantum walk process in the first quantum walk network and the second quantum walk network respectively, and the two quantum walk networks jointly configure the walking process of the quantum walk, realizing remote control and coordination. Since the first quantum walk network and the second quantum walk network are two separate subsystems connected by a quantum optical channel, the limitation of the number of monolithic integrated devices on the existing integrated photonic circuit can be broken through, and the scale of quantum walk can be expanded by using multiple photonic integrated circuits, realizing a larger-scale quantum random walk process, and improving the performance and application potential of the quantum walk system. In addition, the present invention encodes the intermediate state photons of different paths according to time and transmits them through the same quantum optical channel, and then decodes them according to a preset timing to restore the intermediate state photons to the corresponding path. This process avoids the problem that the relative phase of intermediate state photons of different paths is not easy to maintain stability during transmission, and ensures the feasibility and stability of the distributed solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of the structure of a decentralized quantum walk system provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of the connection between the first quantum walk network and the first optical delay array provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of the connection between the second optical delay array and the second quantum walk network provided in an embodiment of the present application;

[0031] Figure 4 A schematic diagram of the structure of a decentralized quantum walk system using an optical waveguide chip as a quantum optical channel provided in an embodiment of the present application;

[0032] Figure 5 A schematic diagram of a first optical switch formed by an MZ interferometer provided in one embodiment of the present application;

[0033] Figure 6 A schematic diagram of a second optical switch formed by an MZ interferometer provided in another embodiment of the present application;

[0034] Figure 7 A schematic structural diagram of a decentralized quantum walk system including a control chip provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0037] like Figure 1 The figure shows a schematic diagram of the structure of a decentralized quantum walking system provided by an embodiment of the present invention, including a first quantum walking network, a first optical delay array, a first optical switch, a quantum optical channel, a second optical switch, a second optical delay array, and a second quantum walking network;

[0038] The first quantum walking network is a photonic network composed of N-level path selection arrays cascaded together. The N-level path selection array includes 2 N-1 path selection units, where N is a positive integer and N ≥ 2. The first-level path selection array includes two initial state input terminals for inputting the initial state photons of quantum walk. Each level of path selection array is used to complete a quantum walk operation; the Nth level path selection array includes 2 NThe intermediate state output port is used to output the intermediate state photons after N quantum walks. Each path selection unit includes two input upper ends, an input lower end, an output upper end, and an output lower end. The first-level path selection array includes 1 path selection unit, the second-level path selection array includes 2 path selection units, the third-level path selection array includes 4 path selection units, and so on. In other embodiments, the Nth-level path selection array includes 2 N -1 Each level of path selection array adopts a tree-like cascade method.

[0039] The first optical delay array includes 2 N N primary photon delay units, the input end of each primary photon delay unit is connected to 2 of the Nth level path selection array N The intermediate state output ports are connected one by one to delay the intermediate state photons output by each intermediate state output port for different time periods. Specifically, the delay time of each delay unit can be set to 0, τ, 2τ, 3τ, ..., (2 N -1)τ; or it can be set to τ, 2τ, 3τ, ..., (2 N -1)τ, 2 N τ.

[0040] The first optical switch includes 2 N An input terminal and an output terminal, 2 N Input terminals and 2 N The output ends of the single-photon delay units are connected one by one, and their output ends are connected to the input end of the quantum optical channel. The first optical switch is used to merge the intermediate state photons output by each single-photon delay unit into the same path, and output them to the quantum optical channel from its output end.

[0041] The quantum optical channel is used to receive and transmit the intermediate state photons output by the first optical switch.

[0042] The second optical switch includes an input terminal and 2 N The output end of the optical switch is connected to the quantum optical channel, and the second optical switch is used to send the intermediate state photons transmitted by the quantum optical channel to the two optical switches according to the preset timing. N output terminals.

[0043] The second delay array includes 2 N The input end of each secondary photon delay unit is connected to the second optical switch. N The output ends are connected one by one to control the 2 NThe intermediate state photons output from the output ends are delayed for different times, so that the intermediate state photons output from each intermediate state output port are output from the output ends of different secondary photon delay units after passing through the first optical switch, the first optical delay array, the quantum optical channel, the second optical switch, and the second photon delay array, and the total delays of the intermediate state photons output from different intermediate state output ports in the first optical delay array and the second photon delay array are equal.

[0044] The second quantum walking network is a photonic network composed of M-level path selection arrays cascaded, and the M-level path selection array includes (2 N-1 +M) path selection units, where M is a positive integer and M≥1; the M-th level path selection array includes 2 N The intermediate state input terminal is used to receive the intermediate state photons output by the second delay array and continue the quantum walk operation. Each level of path selection array in the second quantum walk network is used to complete a quantum walk operation; the (N+M)-th level path selection array includes (2 N +2M) quantum walk state output ports are used to output photons after (N+M) quantum walks.

[0045] Here we take N=3, M=1 as an example (such as Figure 1 As shown). The first quantum walk network is a photon network composed of a cascade of three-level path selection arrays, and the third-level path selection array includes three path selection units arranged in parallel. The first-level path selection array includes two initial state input ports for inputting the initial state photons of the quantum walk, and each level of the path selection array is used to complete a quantum walk operation; the third-level path selection array includes 8 intermediate state output ports for outputting intermediate state photons after three quantum walks. The first optical delay array includes 8 primary photon delay units, and the delay times are 0, τ, 2τ, 3τ, 4τ, 5τ, 6τ, and 7τ, respectively. Figure 2 As shown. The first optical switch includes 8 input ports and one output port; the second optical switch includes one input port and 8 output ports. The second delay array includes 8 secondary photon delay units, and the delay times are 7τ, 6τ, 5τ, 4τ, 3τ, 2τ, τ, and 0, respectively. The intermediate state photons output from each intermediate state output port are output from the output ports of different secondary photon delay units after passing through the first optical switch, the first optical delay array, the quantum optical channel, the second optical switch, and the second photon delay array, and the total delay of the intermediate state photons output from different intermediate state output ports in the first optical delay array and the second photon delay array is equal, that is, 7τ.

[0046] The second quantum walk network is a photon network composed of a cascade of 1-level path selection arrays, in which the 1st-level (M=1) path selection array includes 5 path selection units arranged in parallel. This level of path selection array includes 8 intermediate state input ports for receiving intermediate state photons output by the second delay array and continuing quantum walk operations. The 1st-level path selection array also includes 10 quantum walk state output ports for outputting photons after 4 quantum walks.

[0047] like Figure 2 As shown, the path selection unit includes a phase modulator and a 50:50 beam splitter, and the 50:50 beam splitter includes an input upper end, an input lower end, an output upper end, and an output lower end;

[0048] The phase modulator is connected to the lower input end of the 50:50 beam splitter and is used to input the photons of the path selection unit to perform the coin tossing operation of the quantum walk. The corresponding coin tossing operator is:

[0049] ;

[0050] in, is the phase value modulated by the phase modulator;

[0051] The 50:50 beam splitter is used to perform a shift operation on the photons input into it in the quantum walk, and the corresponding displacement operator is:

[0052] ,

[0053] Where x represents the path number of the photon, or Indicates the coin state. When the coin state is , the photon travels to Position; when the coin state is , the walker reaches Location.

[0054] The phase modulator and the 50:50 beam splitter can be spatial optical devices or on-chip optical devices, that is, the phase modulator and the 50:50 beam splitter are integrated in the same optical chip and optically connected. Figure 2 The second delay array includes 8 secondary photon delay units, and the delay times are 7τ, 6τ, 5τ, 4τ, 3τ, 2τ, τ, and 0, respectively. Figure 3 The intermediate state photons output from each intermediate state output port are respectively output from the output ends of different secondary photon delay units after passing through the first optical switch, the first optical delay array, the quantum optical channel, the second optical switch, and the second photon delay array, and the total delay of the intermediate state photons output from different intermediate state output ports in the first optical delay array and the second photon delay array is equal, that is, 7τ.

[0055] In some embodiments of the present application, the quantum optical channel can be set as a transmission optical fiber, and the first optical switch and the second optical switch form an optical connection with the transmission optical fiber through edge coupling or grating coupling. Through optical fiber transmission, the transmission of intermediate state photons can break through geographical limitations and is not limited to devices on the same platform or in the same device, but can cross regions, thereby realizing distributed quantum walks.

[0056] In other embodiments of the present application, the quantum optical channel can also be configured as an optical waveguide chip, the optical waveguide chip includes a planar waveguide or a three-dimensional waveguide, and the first optical switch and the second optical switch are optically connected to the optical waveguide chip by edge coupling or grating coupling. Figure 4 As shown, the first optical switch and the second optical switch are optically connected to the optical waveguide chip through a grating coupler. In this embodiment, the first quantum walking network, the first optical delay array, and the first optical switch are integrated on one chip, and the second optical switch, the second optical delay array, and the second quantum walking network are integrated on one optical chip.

[0057] In some embodiments of the present application, Figure 5 As shown, the first optical switch is composed of a plurality of MZ interferometers cascaded, and the MZ interferometer includes two input ends and two output ends, and is used to output the photons input from any input end from the same output end. The second optical switch is composed of a plurality of MZ interferometers cascaded, and the MZ interferometer includes two input ends and two output ends, and is used to output the photons input from one of the input ends from the two output ends respectively at a preset timing, such as Figure 6 shown.

[0058] In some embodiments of the present application, the decentralized quantum walk system further includes a control module, which is electrically connected to the first optical switch and the second optical switch, and is used to control the first optical switch and the second optical switch to adjust the photon path; the control module is also electrically connected to the path selection unit, and is used to control each coin tossing operation in the quantum walk. Specifically, the control module can be an electrical control chip, which is integrated with the optical chip through hybrid packaging. Figure 7 shown.

[0059] The embodiment of the present application further provides a decentralized quantum walk method, which is applied to the above-mentioned decentralized quantum walk system, and the method includes:

[0060] Input initial state photons from the two initial state input terminals of the first quantum walking network;

[0061] The path selection arrays at each level of the first quantum walk network complete the quantum walk operation in sequence;

[0062] After N quantum walks, the intermediate state photon changes from 2 NAn intermediate state output port outputs to a first optical delay array;

[0063] The first optical delay array delays the intermediate state photons output from each intermediate state output port by different times;

[0064] The first optical switch combines the intermediate state photons output by each primary photon delay unit into the same path, and outputs them to the quantum optical channel from its output end;

[0065] The quantum optical channel receives and transmits the intermediate state photons output by the first optical switch, and transmits them to the second delay array;

[0066] The second optical switch sends the intermediate state photons transmitted by the quantum optical channel to the 2 N Output terminals;

[0067] The second delay array is connected to the second optical switch 2 N The intermediate state photons output from the output ports are delayed for different times, so that the intermediate state photons output from each of the intermediate state output ports are respectively output from the output ends of different secondary photon delay units after passing through the first optical switch, the first optical delay array, the quantum optical channel, the second optical switch, and the second photon delay array, and the total delays of the intermediate state photons output from different intermediate state output ports in the first optical delay array and the second photon delay array are equal;

[0068] The second quantum walking network receives the intermediate state photons output by the second delay array and continues to perform a quantum walking operation, and each level of path selection array in the second quantum walking network is used to complete a quantum walking operation;

[0069] The (2) of the (N+M)th level path selection array N +2M) quantum walk state output ports output photons after (N+M) quantum walks.

[0070] The various embodiments in this specification are described in a progressive, parallel, or progressive and parallel manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0071] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device.

[0072] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application.

Claims

1. A decentralized quantum walk system, characterized in that: It includes a first quantum walking network, a first optical delay array, a first optical switch, a quantum optical channel, a second optical switch, a second optical delay array, and a second quantum walking network connected in sequence; The first quantum walking network includes two initial state input terminals, a photonic network composed of N-level path selection arrays cascaded, and 2 N intermediate state output ports, which are used to input the initial state photons of quantum walk, complete N quantum walk operations, and output the intermediate state photons after N quantum walks, where N is an integer greater than 1; The first optical delay array includes 2 N A single photon delay unit, and 2 N The intermediate state output ports are connected one by one to delay the intermediate state photons output by each intermediate state output port by different time periods; The first optical switch includes 2 N Input terminal and output terminal, connect 2 N A primary photon delay unit and a quantum optical channel are used to merge the delayed intermediate state photons into the same path and transmit them to the second optical switch via the quantum optical channel; The second optical switch includes an input terminal and 2 N output ends, respectively connected to the quantum optical channel and the second optical delay array, for sending the intermediate state photons transmitted by the quantum optical channel to the second optical delay array in sequence according to a preset timing; The second delay array includes 2 N A secondary photon delay unit, and the 2 N The output ends are connected one by one to the second optical switch. N The intermediate state photons output from each output port are delayed for different times, and the total delay of each intermediate state photon is equal; The second quantum walking network includes 2 N intermediate state input terminals, a photonic network consisting of a cascade of M-level path selection arrays, and (2 N +2M) quantum walking state output terminals are respectively used to receive intermediate state photons and continue quantum walking operations, to complete M quantum walking operations, and to output photons after (N+M) quantum walks, where M is an integer greater than 0.

2. A decentralized quantum walk system according to claim 1, characterized in that: The Nth level path selection array in the first quantum walking network includes 2 N-1 The M-th level path selection array in the second quantum walking network includes (2 N-1 +M) path selection units.

3. A decentralized quantum walk system according to claim 2, characterized in that: The path selection unit includes a phase modulator and a 50:50 beam splitter, and the 50:50 beam splitter includes an input upper end, an input lower end, an output upper end, and an output lower end; The phase modulator is connected to the lower input end of the 50:50 beam splitter and is used to input the photons of the path selection unit to perform a coin tossing operation of the quantum walk. The corresponding coin tossing operator is: ； in, is the phase value modulated by the phase modulator; The 50:50 beam splitter is used to perform a shift operation in quantum walking on the photons input therein, and the corresponding displacement operator is: ， Where x represents the path number of the photon, or Indicates the coin state. When the coin state is , the photon travels to Position; when the coin state is , the walker reaches Location.

4. A decentralized quantum walk system according to claim 1, characterized in that: The first photon delay unit in the first optical delay array is from the first primary photon delay unit to the second primary photon delay unit. N The delay time of each photon delay unit is 0, τ, 2τ...(2 N -1)τ.

5. A decentralized quantum walk system according to claim 1, characterized in that: The quantum optical channel is a transmission optical fiber, and the first optical switch and the second optical switch are optically connected to the transmission optical fiber by edge coupling or grating coupling.

6. A decentralized quantum walk system according to claim 1, characterized in that: The quantum optical channel is an optical waveguide chip, which includes a planar waveguide or a three-dimensional waveguide. The first optical switch and the second optical switch are optically connected to the optical waveguide chip by edge coupling or grating coupling.

7. A decentralized quantum walk system according to claim 2, characterized in that: The first optical switch is composed of a plurality of MZ interferometers cascaded together. The MZ interferometer includes two input ends and two output ends, and is used to output photons input from any input end from the same output end.

8. A decentralized quantum walk system according to claim 2, characterized in that: The second optical switch is composed of a plurality of MZ interferometers cascaded together. The MZ interferometer includes two input ends and two output ends, and is used to respectively output photons input from one of the input ends from the two output ends at a preset timing.

9. A decentralized quantum walk system according to claim 1, characterized in that: The first quantum walking network, the first optical delay array, and the first optical switch are integrated on one chip, and the second optical switch, the second optical delay array, and the second quantum walking network are integrated on one optical chip.

10. A decentralized quantum walk system according to claim 7 or 8, characterized in that: Also included is a control module, the control module is electrically connected to the first optical switch and the second optical switch, and is used to control the first optical switch and the second optical switch to adjust the photon path; The control module is also electrically connected to the path selection unit for controlling each coin tossing operation in the quantum walk.

Images