Improved "Material Calculation"-type Classification Device

Abstract

The sorting device (1) has a pre-processing stage (10), an identification stage (30) and a material system (20) arranged between the pre-processing stage and the identification stage. The material system (20) comprises a non-uniform magnetic medium (50) subdivided into a plurality of regions (51), each region in magnetic communication with at least one adjacent region via a coupling link (53). According to the invention, the material system (20) further comprises control means (71, 73) for setting a coupling value for each coupling link.

Description

[0001] This invention relates to a "material calculation" type classification device.

[0002] The term "materials computing" refers to a method that uses material systems to replicate the operation of artificial neural networks.

[0003] A “materials calculation” device includes a materials system, which is preferably disposed between an input layer and an output layer.

[0004] The input layer preprocesses the signal of interest (i.e. the signal carrying the information to be processed) to obtain multiple input data.

[0005] These multiple input data are applied to the material system, where they are processed according to spatiotemporal processes.

[0006] The state of the material system at the end of this spatiotemporal process is analyzed by the output layer in order to identify the categories used to label signals of interest.

[0007] The material system must possess high dimensionality to exhibit the ability to separate signals of interest in a manner suitable for the classification task performed by the classification device. It must also possess other properties such as short-term memory and local nonlinear response to input data.

[0008] The inventors have filed a patent application (EP 21306379.5) disclosing a classification device comprising a preprocessing stage, an identification stage, and a material system disposed between the preprocessing stage and the identification stage, wherein: the material system comprises a non-uniform magnetic medium subdivided into multiple regions, each region being magnetically communicated directly or indirectly via one or more intermediate regions with at least one so-called source region, each region being either in a first magnetic state (where the magnetization of the region is oriented along a first direction) or in a second magnetic state (where the magnetization of the region is oriented along a second direction opposite to the first direction); the material system includes an initialization module for placing the multiple regions of the magnetic medium in a predefined initial magnetic configuration, wherein the multiple regions other than the source region are in the first magnetic state, and the source region is at least partially The magnetic medium is divided into two magnetic states; a preprocessing stage is adapted to convert the signal of interest into an excitation signal; the material system includes an excitation module adapted to generate a physical excitation quantity based on the excitation signal, the physical excitation quantity being adapted to excite the magnetic medium to move magnetic domain walls located at the interface between the domains of the magnetic medium in the first magnetic state and the domains of the magnetic medium in the second magnetic state, the excitation module applying the physical excitation quantity during a predefined time interval to increase the number of regions in the second magnetic state starting from the source region; the material system includes a readout module adapted to measure the final magnetic configuration reached by the magnetic medium after the application of the physical excitation quantity, the readout signal of the final magnetic configuration being applied as input to an identification stage; and the identification stage is adapted to determine the category to which the signal of interest belongs among a plurality of predetermined categories based on the final magnetic configuration.

[0009] Although the sorting device works properly, its limitation is that once it is manufactured, the magnetic medium is fixed and it is only used for a range of signals that typically have similar frequency responses.

[0010] The purpose of this invention is to propose an improvement to this known classification device.

[0011] Therefore, the present invention relates to an apparatus according to the appended claims.

[0012] The invention and its advantages will be better understood by reading the following detailed description of two embodiments given only as non-limiting examples, which is made with reference to the accompanying drawings, wherein:

[0013] - Figure 1 This is a schematic diagram of the overall function of the classification device according to the present invention;

[0014] - Figure 2 This is a schematic diagram of a first embodiment of the sorting device according to the present invention;

[0015] - Figure 3 It is used for control Figure 2 A schematic diagram of the magnetic control element for the state of the gate in the sorting device shown;

[0016] - Figure 4 It is a schematic block diagram illustrating the usage of the sorting device; and,

[0017] - Figure 5 This is a schematic diagram of an electronically controlled element for controlling the state of a gate in a second embodiment of the classification device according to the present invention;

[0018] In a non-uniform magnetic system, two regions communicate magnetically through a gate.

[0019] In the classification device, information processing is therefore based on the fact that the propagation of the magnetic domain wall depends on the number and diversity of gates it encounters along its propagation path.

[0020] According to the present invention, the state of all or part of the gates is dynamically controlled to adjust the ease or difficulty for the magnetic domain walls to pass through these gates.

[0021] Figure 1 This is a functional schematic diagram of the sorting device according to the present invention.

[0022] The sorting device 1 includes:

[0023] - Preprocessing input level 10;

[0024] - Material System 20; and

[0025] - Identify output level 30.

[0026] Preprocessing stage 10 applies appropriate processing to the signal of interest S0 (i.e., the signal carrying the information to be processed) to obtain the preprocessed signal S. in The preprocessing signal is applied to the material system 20.

[0027] Material system 20 includes:

[0028] - A non-uniform magnetic medium 50 is subdivided into multiple regions or chambers, each of which communicates magnetically with at least one other chamber via a gate. Each chamber is either in a first magnetic state, wherein the magnetization of the chamber is oriented along a predefined reference direction, or in a second magnetic state, wherein the magnetization of the chamber is parallel to a direction opposite to the predefined reference direction.

[0029] - Initialization device 21, used to place the chamber of medium 50 in the initial magnetic configuration;

[0030] - Excitation device 22, for applying an excitation signal S onto the medium ext, so that the domain walls between oppositely magnetized domains will move through the medium 50, thereby reaching the final magnetic configuration from the initial magnetic configuration;

[0031] - Readout device 24, used to read the final magnetic configuration of the medium and generate an output signal S out ;as well as,

[0032] - Construction device 23, used to set the state of each coupling gate of medium 50.

[0033] refer to Figure 2 In the first embodiment, the non-uniform magnetic medium 50 is a two-dimensional medium, such as a rectangular shape. Its thickness is much smaller than its characteristic length and width. Alternatively, other geometries besides rectangles may be used.

[0034] The medium 50 is, for example, composed of a stack of multiple layers, wherein at least one layer is made of a magnetic material whose magnetization can be modified. For example, the non-uniform magnetic medium 50 includes three layers 41, 42 and 43, for example, Pt, Co and Pt, respectively.

[0035] For example, the magnetization of the intermediate layer 42 is oriented along a reference direction perpendicular to the plane of the medium 50.

[0036] In this first embodiment, the non-uniform magnetic medium 50 is provided with a plurality of chambers 51. It is these chambers that make the magnetic medium non-uniform.

[0037] The chamber 51 is defined by a wall 54 and has at least one door 53 for communicating with adjacent chambers.

[0038] A door is positioned through the walls of the chambers. The door allows the domain walls to move between the two chambers connected by the door. As described below, the state of door 53 can be controlled individually. For example, in a simple embodiment, a door 53 may be closed (or nearly closed, i.e., low coupling between the two chambers to prevent or limit movement of the domain walls) or open (or nearly open, i.e., high coupling between the two chambers to facilitate movement of the domain walls). In more interesting embodiments, the state of a door is modulated between several possible states, or even along consecutive states.

[0039] The chamber can have different geometries. Figure 2 In this case, chamber 51 is rectangular, but has varying length and / or width. Alternatively, other geometries are also possible, such as chambers with n sides (n is greater than or equal to 3 and typically less than 10).

[0040] exist Figure 2 In this configuration, the door 53 between two adjacent chambers is arranged in the form of a corridor, parallel to the two sides of the interconnecting chamber 51. The door can have different lengths, widths, and positions on the wall.

[0041] Alternatively, a chamber can have more than one door.

[0042] Any chamber 51 can be accessed from the chamber of medium 50, referred to as the source chamber 52, via one or more paths through a variable number of intermediate chambers (which may be zero).

[0043] As the domain walls move under the influence of an excitation, they propagate along one or more such paths.

[0044] The final magnetic configuration is obtained after applying an excitation.

[0045] The cavity 51 is fabricated by locally modifying the magnetic material of the medium 50 to make it nonmagnetic or discontinuous, thus defining the walls 54 and the gate 53. For example, this can be achieved by etching the magnetic material through a mask made of resin or a sacrificial material (metal, dielectric, etc.), the design of which has been predefined in the mask via optical or electrolithography steps. Alternatively, the cavity 51 can be fabricated using a focused laser with sufficient intensity to locally render the magnetic material nonmagnetic.

[0046] Each chamber 51 thus defines a region whose magnetization can be oriented along a reference direction M1, thus placing the chamber in a first magnetic state, or along the opposite direction M2, thus placing the chamber in a second magnetic state. In this embodiment, the reference direction is perpendicular to the plane of the medium 50. This is illustrated in the figures by white boxes to indicate the chamber in the first state and dashed boxes to indicate the chamber in the second state.

[0047] In this embodiment, the chambers are adjacent to each other, making the non-uniform magnetic medium compact.

[0048] In addition to the non-uniform magnetic medium 50, the material system 20 also includes a coil 25 as a means of generating a magnetic field. The coil 25 is arranged in close proximity to the medium 50 (e.g., above or below the medium 50) such that it can generate a substantially uniform magnetic field oriented along a reference direction throughout the medium 50.

[0049] The initialization device 21 of the material system 20 includes a coil 25 and an initialization module 121, which enables the non-uniform magnetic medium 50 to be set in a predefined initial magnetic configuration by providing an appropriate current to the coil 25, so that any classification task can start from the same and known magnetic configuration of the medium 50.

[0050] The initial magnetic configuration is defined, for example, as a configuration in which all chambers 51 except the source chamber 52 are in a first magnetic state M1, and the source chamber 52 is at least partially placed in a second magnetic state M2.

[0051] In the first embodiment, the initialization module 121 includes, for example, a reset block 122 and a nucleation block 124, which are connected to the coil 25 so that an appropriate current can be supplied to it.

[0052] When powered by the reset block 122, the coil 25 generates a first magnetic field B1 parallel to the reference direction, and this magnetic field is strong enough across the entire surface of the magnetic material to align the magnetization of each chamber 51 parallel to the reference direction, i.e., to set all chambers to the first magnetic state M1. The reset block 122 thus places the dielectric 50 in a uniform magnetic configuration.

[0053] In order to enable the medium 50 to be in the initial magnetic configuration, local defects are introduced in the magnetic material of the source chamber 52 to ensure that magnetic domains nucleate at that precise location when the second magnetic field B2 is applied.

[0054] The coil 25 is then powered by the nucleating block 124 to generate the second magnetic field B2. This field is antiparallel to the reference direction and is locally strong enough to switch only a defined portion of the magnetization of the source chamber 52 to the second magnetic state M2.

[0055] Alternatively, the reset block or nucleation block may be associated with a dedicated magnetic field generating device. For example, the nucleation module drives an electromagnet positioned near (e.g., directly above or below) the source chamber 52 to generate a second magnetic field suitable for nucleation. In this case, defects in the source chamber material may no longer be necessary.

[0056] Alternatively, any means known to those skilled in the art that can modify the configuration of medium 50 to set it to a predefined initial magnetic configuration and nucleate magnetic domains in the source chamber if necessary can be used. For example, an electric field or current can be used instead of a magnetic field.

[0057] Alternatively, the initial magnetic configuration results in the medium exhibiting multiple source regions. If a nucleation module is implemented, it then allows the different source regions to be at least partially placed in a second magnetic state. The nucleation module then includes, for example, multiple electromagnets arranged adjacent to each source region to generate a second magnetic field suitable for modifying the magnetization of a portion of each source region, the magnetization being antiparallel to a reference direction. Alternatively, local defects are introduced into the magnetic material of each source region to ensure that magnetic domains nucleate in each source region when the second magnetic field is applied, the second magnetic field being generated, for example, by means of an extended coil such as coil 25.

[0058] The excitation device 22 of the material system 20 includes a coil 25 and an excitation module 126 connected to the coil 25. The excitation module 126 provides the coil 25 with a suitable excitation magnetic field B during predefined time intervals. extThe current. In this first embodiment, the current source generated by module 126 is free from the input signal S transmitted by the preprocessing input stage 10. in .

[0059] Excitation magnetic field B ext It is capable of moving the domain walls, that is, the interface between a domain in the first magnetic state and a domain in the second magnetic state.

[0060] Alternatively, the excitation module may be associated with a dedicated device for generating physical excitation quantities, which is independent of other components of the material system.

[0061] Alternatively, the excitation module can make the physical excitation quantity an electric field or current instead of a magnetic field.

[0062] The readout device 24 of the material system 20 includes a magnetic sensor array 61 and a readout module 62 for determining the final magnetic configuration of the non-uniform magnetic medium 50 after being subjected to a physical excitation. Each magnetic sensor 61 is located very close to a corresponding chamber 51. It measures whether the chamber is in a first magnetic state M1 or a second magnetic state M2. The readout module 62 collects signals from each magnetic sensor 61 and generates a readout signal S. out This is to transmit information to identification level 30.

[0063] The recognition level 30 is preferably composed of an artificial neural network. This artificial neural network is configured to determine the category to which the signal of interest belongs among multiple predefined categories. This determination is based on the final magnetic configuration of the non-uniform magnetic medium to which the signal of interest is located. The artificial neural network can be simple, such as a "perceptron," so that complex calculations need not be performed, especially during the learning phase. Alternatively, the artificial neural network can contain multiple layers.

[0064] The construction device 23 of the material system 20 includes a control element 73 associated with each gate 53 for modulating the coupling characteristics of that gate, and a construction module 71 for addressing each control element 73. Figure 2 For clarity, only three control elements 73 are shown. Alternatively, only a subset of the gates of the medium may be associated with the control elements.

[0065] Control element 73 is positioned on magnetic medium 50, directly above the door 53 it controls. Control element 73 is designed to reversibly control local values ​​of certain physical parameters affecting the magnetic coupling value of the door, thereby influencing the propagation of magnetic domain walls through the door between the two connecting chambers. This coupling value defines the state of the door.

[0066] In the first embodiment, the control element is a magnetic control element.

[0067] The function of a magnetron is to generate a local magnetic field, such as to create either a potential barrier that allows magnetic domain walls to move through a door (open state) or an opposite potential barrier that restricts movement through a door (closed state).

[0068] Magnetically controlled elements, for example, have the following characteristics: Figure 3 The structure shown.

[0069] The magnetizing element 173 has a magnetic layer 84 that is magnetized, for example, perpendicular to the plane of the medium 50. The direction of magnetization can be modified, for example, upward to put the door in the closed state, and downward to put the door in the open state.

[0070] The magnetic layer 84 is, for example, Co and Pt, or Co and Pd, or Co, or Ni, or an alloy of the CoNi, CoPt type, or any other multilayer of material with perpendicular magnetization.

[0071] Alternatively, the magnetic layer with planar magnetization will be made of materials such as NiFe, Co, CoFe, CoFeB, or any other material with planar magnetization.

[0072] Once established, the magnetization is fixed, meaning it cannot be modified by the propagation of domain walls in the medium, nor by the excitation amount used to propagate domain walls, and preferably cannot be modified by the initialization location of placing the material system in the initial magnetic configuration.

[0073] The magnetic layer 84 is preferably placed on the dielectric 50 via the contact layer 83. The contact layer is made of a non-magnetic material, which may be a dielectric, such as MgO, AlOx, etc., or a conductive material, such as Cu, Ru, Ir, Pt, etc.

[0074] The change of magnetization direction of the magnetic layer is preferably achieved by an electrical means, such as by a spin-transfer torque-STT mechanism.

[0075] In this case, the magnetically controlled element can be configured as a spin valve or a magnetic tunnel junction. It then includes:

[0076] - Layer 87 made of a non-magnetic metal (e.g., Cu or MgO).

[0077] - The so-called reference magnetic layer 88 has a fixed magnetization.

[0078] - Additional layers 89 for appropriate functions of layer stacking, such as well-known spin valves and magnetic tunnel junctions.

[0079] - Conductive electrode 80.

[0080] By applying a suitable voltage to the electrode 80 through a voltage source 81 (e.g., embedded in module 71), magnetization can be set in one direction or another depending on the state to be set by the corresponding gate 53.

[0081] Setting the magnetization in one direction or another will either facilitate or impede the passage of domain walls from one chamber to the next. Using this type of magnetocontrol element, the control of the bottom gate is binary.

[0082] Figure 4 The usage instructions are shown.

[0083] According to method 200, the classification device 20 is used to perform the classification task.

[0084] In step 210, the construction device 23 is used to set the state of each door. Multiple doors maintain this state throughout the sorting task.

[0085] In step 220, the medium 50 is first reinitialized using device 21 to place the medium in the initial magnetic configuration.

[0086] In step 230, the first signal of interest is encoded into the form of an excitation magnetic field, which is then applied to the medium 50 by the excitation device 22 to move the magnetic domain walls.

[0087] In step 240, the reading device 24 is used to read the final magnetic configuration achieved by the medium 50.

[0088] In step 250, the readout signal is transmitted to identification level 30 for identifying the category to which the signal of interest belongs.

[0089] After classifying the first signal of interest, multiple gates can be constructed to iterate over the same classification task (i.e., iterations of steps 230, 240, and 250), but over a second signal of interest that is different from the first signal of interest.

[0090] Alternatively, the construction of multiple gates can be modified to perform a different sorting task. This makes the sorting device adaptable for different specific applications.

[0091] The construction of multiple gates can also be modified to perform another classification task, still targeting the first signal of interest. Thus, the signal is processed again, but using a different material system. This possibility allows for more complex processing without increasing the physical size of the material system.

[0092] The configuration of multiple gates can be determined based on the response of the entire material system 20 or a sub-system of material system 20. This is particularly useful, for example, when the initially selected state for the gates is unsuitable for the signal to be processed and the classification task to be performed. For example, consider a gate that is very difficult to pass through, i.e., the pulse sequence constituting the signal does not allow the domain walls to reach the barrier threshold for passing through the gate. In this case, the rest of the signal cannot be processed because it is blocked at the gate. The presence of such a strong trapping center for the signal to be processed would be very detrimental to the classification task. More generally, signal processing analysis allows it to determine whether the configuration of the gates in the system is suitable for the signal to be processed and whether it needs to be modified. This is advantageously performed in the initial development phase of the classification device to identify the gate configuration, thereby optimizing the classification task.

[0093] The database is divided into a first database for training and a second database for inference. A portion of the first database is also used for analysis and determining appropriate configurations (typically about 5% or less of the training database).

[0094] We begin by using the files stored in that section of the first database. After testing several files, we then check if the gates are too congested, or even completely blocked, or conversely, if they allow domain walls to pass too easily (typically after a few pulses or even a single pulse). We then adjust the coupling of the target gate (preferably in a continuous or quasi-continuous manner). We begin a new test. One iteration may suffice, but more often multiple iterations are necessary (typically, if a gate is too congested, it will prevent the testing of subsequent gates, which can also cause problems and must be adjusted).

[0095] Then the rest of the training database is used to train recognition level 30.

[0096] The second embodiment will now be described.

[0097] One of the limitations of the first embodiment is related to the high energy consumption required to excite the medium by a variable magnetic field.

[0098] In this second embodiment, the excitation device 22 generates an excitation quantity, which is a constant magnetic field B. ext For example, device 22 can be a permanent magnet. Simultaneously, the input signal S... in Applied to the construction device 23 S ext .

[0099] A permanent magnet is placed near the medium to apply a constant magnetic field capable of moving domain walls at any point in the medium. The amplitude of this magnetic field is typically between 1 mT and 5 mT. However, this magnetic field is insufficient for the nucleation of new domains. By using a permanent magnet, the medium can be excited without consuming any energy.

[0100] The signal to be processed is now used to control the state of the door.

[0101] Since the input signal is analog, in this second embodiment, the control element is preferably an electronically controlled element. It generates a local electric field that modifies the potential barrier in the magnetic material at the gate to control the propagation of magnetic domain walls. The electric field will locally modify the properties of the magnetic material, such as, for example, anisotropy or the DMI constant (Dzyaloshinskii-Morya interaction - DMI constant). An advantage of using an electric field is that the state of the gate can be continuously controlled using a simple voltage.

[0102] For example, Figure 5 As shown, the electronic control element 373 includes an electrode 380 placed on the magnetic medium 50 above the gate 53 to be controlled. Preferably, a contact layer 383 is inserted between the electrode and the medium.

[0103] Typical materials used for electrode 380 are conductive materials, such as Pt, Al, Ir, Ru, Cu, Au, Pd, etc. Contact layer 383 is composed of dielectric materials, such as AlOx, MgOx, ZnOx, SiOx, etc. This material must be electrically insulated, and other materials besides oxides can also be used.

[0104] An electrode 380 is connected to a control line 390 via an address control transistor 382, ​​which is controlled via its gate.

[0105] The magnetic state of a chamber 51 is read by sensor 361. Sensor 361 operates, for example, as a magnetic tunnel junction, which consists of a dielectric 50 (acting as the lower electrode of the tunnel junction), an insulating layer 363 (typically made of MgO), and a layer stack 362 (specifically defining a magnetic reference layer and an upper electrode). This layer stack 362 is connected to a readout line 392 via an addressable readout transistor 364. The readout line 392 allows the reading of the resistance state of each sensor 361, as is typically done in MRAM technology.

[0106] Control line 390 is supplied with a voltage sufficient to cause the state of the bottom gate 53 to change as required by voltage generator 391. This voltage is typically -10V to +10V, preferably -5V to +5V, and most preferably -2V to +2V.

[0107] Therefore, by the permanent magnetic field B ext The pushed domain walls pass through a gate more or less easily depending on the applied voltage.

[0108] Input signal S from preprocessing stage 10 inThe input signal is applied to the gate of the address control transistor 382. This input signal is, for example, in the form of a time sequence of constant-amplitude pulses. It is applied simultaneously to all the address control transistors 382. Each of these transistors thus turns on and off simultaneously by the pulses applied to its gate.

[0109] Alternatively, addressing control transistors do not necessarily have to be used in on / off switching mode. They can also be used in analog mode.

[0110] This allows for coupling between continuously modulated chambers.

[0111] The ability to define the state of a gate without requiring any current further helps to reduce the energy consumption of this second embodiment.

[0112] This second embodiment can have several alternatives:

[0113] The input signal can be sent to only a portion of the gates in a first time interval, which is less than the duration of the signal of interest to be processed, and then sent to another portion of the gates in a second time interval.

[0114] - The preprocessed signal is applied as a voltage to control line 390, instead of to the gate of the address control transistor. The address control transistor 382 is either turned on or simply replaced by a connection line.

[0115] The second embodiment only requires the fabrication of electrodes, which can be easily manufactured using conventional micro / nano fabrication techniques.

[0116] In other alternatives, the control element used to control the state of a door is a thermal control element, rather than a magnetic or electrical control element.

[0117] In this case, local temperature changes are generated in order to locally alter the magnetic properties of the medium in a manner that defines the possible states of the gate.

[0118] For example, a resistive element is placed on the medium directly above the door for control. When an electric current is applied, the resistive element is heated through the Joule effect.

[0119] Alternatively, localized heating can be generated through radiation, such as a laser beam. In this case, intermediate elements can be added to optimize heating, such as a layer that has high absorption of the laser beam at a specific wavelength.

[0120] Any known methods capable of locally modifying domain wall propagation include pinning, unpinning, and modification of propagation velocity. For example, it has recently been reported that the presence of surface acoustic waves can facilitate unpinning of domain walls.

[0121] As mentioned above, only some of the doors are controllable. Alternatively, several doors may be controlled by the same control element.

[0122] This invention allows for the modification of material systems to make them even more versatile. This enables the analysis of very different signals of interest from various databases or with very different frequency characteristics.

[0123] The coupling link between two regions is not always "hard-structured" in the medium like a gate, but is defined by electrodes placed vertically on the medium at the interface between the two regions. The medium then acts like a long corridor with the electrodes distributed throughout. The electrodes then apply an electric field to modulate the local properties of the medium.

Claims

1. A sorting apparatus (1) comprising a pretreatment stage (10), an identification stage (30), and a material system (20) disposed between the pretreatment stage and the identification stage. The classification device is characterized in that: - The material system (20) includes a non-uniform magnetic medium (50), which is a magnetic medium subdivided into multiple regions (51), each region being either in a first magnetic state, wherein the magnetization (M1) of the region is oriented along a first direction, or in a second magnetic state, wherein the magnetization (M2) of the region is oriented along a second direction opposite to the first direction, each region in the multiple regions being magnetically communicated with at least one adjacent region in the multiple regions via a coupling link characterized by a magnetic coupling value, each region in the multiple regions being magnetically communicated directly or indirectly with a source region (52) in the multiple regions via one or more intermediate regions in the multiple regions; - The material system (20) includes an initialization device (21) for placing a plurality of regions (51) of the non-uniform magnetic medium (50) in a predefined initial magnetic configuration, wherein the plurality of regions other than the source region (52) are in a first magnetic state, and the source region is at least partially placed in a second magnetic state. - The preprocessing stage (10) is adapted to convert the signal of interest (S0) into a preprocessed signal (S). ext ); - The material system (20) includes an excitation device (22) for generating a physical excitation amount suitable for exciting the non-uniform magnetic medium (50) to move domain walls (56) located at each interface between a first region of the non-uniform magnetic medium (50) in a first magnetic state and a second region of the non-uniform magnetic medium (50) in a second magnetic state, the excitation device (22) applying the physical excitation amount during a predefined time interval to increase the number of second regions in the second magnetic state starting from the source region (52); - The material system (20) includes a readout device (24) for measuring the magnetic state of the plurality of regions after the physical excitation is applied in order to define the final magnetic configuration reached by the non-uniform magnetic medium (50), the final magnetic configuration being applied as input to the identification level (30). - The identification level (30) is adapted to determine, based on the final magnetic configuration, the category (C) to which the signal of interest (S0) belongs among a plurality of predetermined categories. i );as well as, - The material system (20) includes a control device (23) for reversibly and dynamically setting the coupling value of one or more coupling links.

2. The classification device (1) according to claim 1, wherein the excitation device (22) is based on the preprocessing signal (S) in This generates the physical excitation quantity.

3. The classification device (1) according to claim 1, wherein the control device (23) is based on the preprocessing signal (S) in Adjust the coupling value of at least one coupled link.

4. The classification device (1) according to claim 3, wherein the excitation device (22) comprises a permanent magnet.

5. The classification device (1) according to any one of claims 1 to 4, wherein the coupling link includes a gate (53) defined in the medium (50) and a control element (173, 373) for defining the current state of the gate.

6. The sorting device (1) according to any one of claims 1 to 5, wherein the control device is a magnetic control device (173).

7. The sorting device (1) according to any one of claims 1 to 5, wherein the control device is an electronic control device (373).

8. The classification device (1) according to any one of claims 1 to 7, wherein the coupling value of each coupling link is selected from a plurality of discrete values, the plurality of discrete values ​​defining a plurality of states of the corresponding coupling link.

9. The classification device (1) according to any one of claims 1 to 7, wherein the coupling value of each coupling link is selected in a value range that defines the continuous state of the corresponding coupling link.

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