Network comprising plurality of oscillators

Abstract

A network includes a plurality of oscillators. The network is configured to control the phases of the plurality of oscillators by thermal coupling via a thermal link.

Description

[0001] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] The project leading to the present application has received funding from the European Union's Horizon 2020 research and innovation programme under Marie Skwodowska-Curie GrantAgreementNo.861153. Background Art

[0003] The present invention generally relates to oscillators. Summary of the invention

[0004] According to embodiments, a network, a method, and a computer program product are disclosed.

[0005] According to an embodiment, the present invention is embodied in a network comprising a plurality of oscillators. The network is configured to control the phases of the plurality of oscillators by thermal coupling via a thermal link.

[0006] The above summary is not intended to describe each illustrated embodiment or every implementation of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings included in this application are incorporated into the specification and form a part of the specification. They illustrate embodiments of the present disclosure and, together with the specification, are used to explain the principles of the present disclosure. The accompanying drawings are only illustrations of certain embodiments and do not limit the present disclosure.

[0008] Figure 1 A network according to an embodiment of the present invention is shown;

[0009] Figure 2 Another network according to an embodiment of the present invention is shown;

[0010] Figure 3 Another network according to an embodiment of the present invention is shown;

[0011] Figure 4 Another network according to an embodiment of the present invention is shown;

[0012] Figure 5 Another network according to an embodiment of the present invention is shown;

[0013] Figure 6 Another network according to an embodiment of the present invention is shown;

[0014] Figure 7 Another network according to an embodiment of the present invention is shown;

[0015] Figure 8 Another network according to an embodiment of the present invention is shown;

[0016] Figure 9a 9c shows a network configured to perform adaptive thermal coupling, wherein

[0017] Figure 9a Negative coupling is shown;

[0018] Figure 9b Positive coupling is shown;

[0019] Figure 9c shows decoupling; and

[0020] Fig.10 A flow chart showing method steps of a method according to an embodiment of the invention is shown.

[0021] Although the present invention can be subjected to various modifications and alternative forms, its details have been shown by the examples in the accompanying drawings and will be described in detail. However, it should be understood that the purpose is not to limit the present invention to the specific embodiments described. On the contrary, the purpose is to cover all modifications, equivalents and substitutes falling within the scope of the present invention. DETAILED DESCRIPTION

[0022] The present invention generally relates to oscillators.

[0023] Such a network can be embodied as an oscillatory neural network (ONN) and can be used as a hardware implementation of neuromorphic computing. By using an oscillatory neural network, a neural network can be formed in which information is encoded in the frequency or phase of the oscillators. The coupling elements between the individual oscillators can be used for signal processing similar to the function of synapses.

[0024] Such networks of coupled oscillators can perform classification as well as optimization tasks and can be used as hardware accelerators for the first layer of filters in convolutional neural networks.

[0025] Embodiments use a relaxation oscillator of VO2 resistors.

[0026] Oscillatory neural networks may offer advantages in terms of robustness, speed, and power efficiency, and may be particularly useful as input filters for feature detection in image recognition.

[0027] Therefore, advanced solutions for such networks are needed.

[0028] According to one aspect, the invention is embodied in a network comprising a plurality of oscillators. The network is configured to control the phases of the plurality of oscillators by thermal coupling via a thermal link.

[0029] Such a network may offer advantages in terms of energy efficiency, since heat dissipation of the components of the oscillator is used for phase control.

[0030] Furthermore, such a network may provide advantages in terms of area efficiency and ease of manufacture, since thermal coupling may be achieved without additional circuitry such as coupling capacitors and coupling inductors. In particular, capacitors require significantly more space than arranging thermal coupling.

[0031] According to an embodiment, hot links for phase control may enable faster and denser oscillating networks with lower power consumption and higher operating speeds.

[0032] According to an embodiment, the thermal coupling comprises an anti-phase coupling. According to an embodiment, the thermal coupling comprises an in-phase coupling.

[0033] Such a network with positive and negative thermal coupling can be useful for a wide range of applications.

[0034] According to an embodiment, a network comprises a plurality of electrical links for electrically coupling a plurality of oscillators.

[0035] According to an embodiment, the network may be a neural network and the plurality of oscillators form an oscillating neural network. In particular, the neural network may be a hardware implementation of an artificial neural network.

[0036] According to an embodiment, the oscillator is embodied as a relaxation oscillator. Each oscillator of the plurality of oscillators may include a self-heating solid-state phase change device, the solid-state phase change device including a phase change material having a first phase state and a second phase state. The first phase state may be a low resistance state, and the second phase state may be a high resistance state. The first phase state may in particular be a metallic state, and the second phase state is an insulating state.

[0037] Such relaxation oscillators facilitate dense integration of networks.

[0038] According to an embodiment, the plurality of oscillators include a first oscillator and a second oscillator, the first oscillator including a first series arrangement of a first self-heating phase change device and a first series resistor, and the second oscillator including a second series arrangement of a second self-heating phase change device and a second series resistor. The first series resistor may be thermally coupled to the second self-heating phase change device, thereby achieving unidirectional thermal coupling between the first oscillator and the second oscillator.

[0039] According to an embodiment, the network further comprises one or more thermal waveguides for facilitating thermal coupling.

[0040] According to an embodiment, the network further comprises one or more thermal separation structures etched into a substrate of the network, the one or more thermal separation structures being configured to provide thermal isolation between two or more oscillators of the plurality of oscillators.

[0041] According to an embodiment, the series resistor may be realized as a transistor or a memristor or any resistive element. According to an embodiment, the arrangement may comprise an electrical coupling element (memristor) in addition to the thermal link.

[0042] This network with unidirectional coupling provides advanced applications with enhanced flexibility.

[0043] According to an embodiment, the network is configured to perform adaptive thermal coupling between two or more oscillators of the plurality of oscillators by adjusting the oscillation frequency of one or more oscillators of the plurality of oscillators, thereby changing the thermal coupling mode. According to an embodiment, the thermal coupling mode may include bidirectional coupling, unidirectional coupling and / or non-coupling. According to an embodiment, adjusting the oscillation frequency may include changing one or more parameters of the electrical components of the network.

[0044] This network with adaptive thermal coupling provides advanced applications with enhanced flexibility.

[0045] According to an embodiment, one or more oscillators of the plurality of oscillators comprise two or more adjustable resistors, wherein only one of the two or more adjustable resistors is thermally coupled to another oscillator of the plurality of oscillators. This allows other applications. In particular, it can be achieved that the total resistance of the adjustable resistors remains constant and thus the electrical characteristics of the network or circuit do not change, however the coupling between the oscillators can be adjusted.

[0046] According to an embodiment, a method for operating a network comprising a plurality of oscillators comprises the steps of controlling the phases of the plurality of oscillators by thermal coupling via a thermal link.

[0047] According to an embodiment, a computer program product for operating a network includes a plurality of oscillators and a plurality of hot links. The computer program product includes a computer-readable storage medium containing program instructions executable by the network to perform a method including controlling the phase of the plurality of oscillators by thermal coupling via the hot links.

[0048] Embodiments of the invention will be described in more detail below by way of illustrative and non-limiting examples with reference to the accompanying drawings.

[0049] refer to Figures 1 to 10 , describes some general aspects and terms of embodiments of the present invention.

[0050] A heat wave is a time-varying temperature field around a heating element with a periodically varying temperature.

[0051] The thermal wave changes sign at a distance of about 2356η (normalized distance), where

[0052]

[0053] In the above equation, α represents the thermal diffusivity of the corresponding material through which the heat wave propagates, such as the thermal diffusivity of the substrate of the network, and ω=2πf represents the angular frequency of the heat wave, where f is the common frequency in Hz.

[0054] According to an embodiment, both coupling and anti-coupling between oscillators of the network may be achieved depending on the coupling material, the frequency of the thermal waves and the distance between the corresponding elements.

[0055] Figure 1 A network 100 according to an embodiment of the present invention is shown. The network 100 includes a first oscillator 110 and a second oscillator 120. The first oscillator 110 and the second oscillator 120 can be specifically embodied as relaxation oscillators. The first oscillator 110 includes an oscillating element 111, and the second oscillator 120 includes an oscillating element 121. The oscillating element 111 and the oscillating element 121 can in particular include an element having a current-voltage diagram similar to an s-shape. According to an embodiment, the oscillating element 111 and the oscillating element 121 are embodied as self-heating solid-state phase change devices. The solid-state phase change device includes a phase change material having a first phase state and a second phase state. According to an embodiment, the first phase state can be a metallic state, and the second phase state can be an insulating state. The solid state phase change material may be, for example, VO2, V4O7, V6O11, V2O3, V6O13, V5O9, VO, V8O15, NbO2, Ti2O3, LaCoO3, Ti3O5, SmNiO3, NdNiO3, PrNiO3 or Fe3O4.

[0056] The first oscillator 110 includes a series resistor or resistive element 112, which is arranged in series with the oscillating element 111. The second oscillator 120 includes a series resistor 122, which is arranged in series with the oscillating element 121. The first oscillator 110 may also include a capacitor 113 arranged in parallel with the series resistor 112. The second oscillator 120 may also include a capacitor 123 arranged in parallel with the series resistor 122. According to an embodiment, the capacitor may be connected in parallel with the oscillating element so that the oscillating element and the capacitor form a parallel arrangement. In addition, there may be a resistive element in series with the parallel arrangement. The first oscillator 110 receives an input voltage V in1 , the second oscillator 120 receives an input voltage V in2 . Input voltage V in1 and V in2 It is manifested as a DC voltage.

[0057] The network 100 is configured to control the phase of the first oscillator 110 and the second oscillator 120 by thermal coupling via a thermal link 130. According to embodiments, the thermal link 130 may be implemented in several different ways. According to some embodiments, the thermal link 130 may be configured so that an anti-phase coupling is achieved between the first oscillator 110 and the second oscillator 120. According to embodiments, the thermal link 130 may be configured so that an in-phase coupling is achieved between the first oscillator 110 and the second oscillator 120. The respective coupling modes between the first oscillator 110 and the second oscillator 120 may be achieved in various ways and specifically depend on the respective coupling materials, the frequency of the thermal waves, and the distance between the respective elements involved in the thermal coupling.

[0058] The network 100 may in particular be configured as a neural network. According to such an embodiment, the oscillator 110 , the oscillator 120 and the plurality of further oscillators may form an oscillatory neural network.

[0059] Optionally, the network 100 may comprise an electrical link 140 for electrically coupling the first oscillator 110 and the second oscillator 120. This is shown with a dashed line.

[0060] Figure 2 A network 200 according to an embodiment of the present invention is shown. The network 200 includes a first oscillator 210 and a second oscillator 220. The first oscillator 210 and the second oscillator 220 are embodied as relaxation oscillators including self-heating solid-state phase change devices. For ease of illustration, only the self-heating solid-state phase change devices 211 and 221 of the first oscillator 210 and the second oscillator 220 are shown.

[0061] The first oscillator 210 and the second oscillator 220 are arranged at a predetermined radial distance r from each other. Figure 2 , the respective predetermined radial distance r from the first oscillator 210 is shown with the horizontal axis 240. More specifically, the second oscillator 220 is arranged at a distance d of 2.356η from the first oscillator 210. This results in a negative thermal coupling, or in other words an anti-phase thermal coupling. The thermal coupling may in particular be achieved by thermal substrate coupling, for example, the respective thermal waves pass through a common substrate on which the first oscillator 210 and the second oscillator 220 are arranged. According to an embodiment, at a distance d of 2.356η, the phase delay of the thermal wave passing through the substrate will be The desynchronization between the first oscillator 210 and the second oscillator 220 is thus enhanced. The corresponding time Δt between the peak heat dissipation in the first oscillator 210 (reference) and the propagation of heat through the substrate to the surrounding environment is Figure 2 241 and the corresponding phase delay between the peak heat dissipation in the first oscillator 210 (reference) and the propagation of heat through the substrate to the surrounding environment. As shown by horizontal axis 242. Thus, there is an area of ​​positive coupling 251 and an area of ​​negative coupling 252. According to an embodiment, first oscillator 210 and second oscillator 220 bidirectionally influence each other because both send and receive thermal waves to each other. Horizontal axis 242 shows the coupling phase with gray shading. Black represents phase delay White indicates phase delay

[0062] Figure 3 A network 300 according to an embodiment of the present invention is shown. Figure 3 In an embodiment, several oscillators can be placed in the negative coupling region of the first oscillator 1. More specifically, the network 300 includes a plurality of n oscillators, represented as oscillator 1, oscillator 2, ..., oscillator n. The n oscillators are embodied as relaxation oscillators including self-heating solid-state phase change devices. For ease of illustration, only the self-heating solid-state phase change devices 311, 321, ..., 3n1 of each of the n oscillators are shown.

[0063] Oscillator 2 and further oscillators 3, ..., n are arranged at a predetermined radial distance r from oscillator 1. This is shown by horizontal axis 340. More specifically, each of oscillator 2 and further oscillators 3, ..., n is arranged at a radial distance d of 2.356η from oscillator 1. This results in negative thermal coupling, or in other words in anti-phase thermal coupling. At a distance d of 2.356η, the phase delay of the thermal wave passing through the substrate will be Thus, the desynchronization between oscillator 1 and oscillators 2, 3, ..., n is enhanced. Figure 3 In the configuration, oscillator 1 is negatively coupled to oscillator 2 and further oscillators 3, ..., n, while oscillators 2 to n are positively coupled to each other.

[0064] The corresponding time Δt between the peak heat dissipation in oscillator 1 (reference) and the heat propagation through the substrate to the surrounding environment is Figure 3 , and the corresponding phase delay between the peak heat dissipation in oscillator 1 (reference) and the propagation of heat through the substrate to the surrounding environment. This is shown by the horizontal axis 342. Thus, there is an area 351 of positive coupling and an area 352 of negative coupling. The horizontal axis 342 shows the coupling phase in grey shading. Black represents the phase delay White indicates phase delay

[0065] Figure 4A network 400 according to another embodiment of the present invention is shown. The network 400 includes three oscillators 410, 420, and 430 in an equilateral triangle configuration. Therefore, all three oscillators 410, 420, and 430 may be spaced apart by a distance of ˜2.356η. Therefore, according to an embodiment, all three oscillators 410, 420, and 430 may be negatively coupled to each other.

[0066] Figure 5 A network 500 according to another embodiment of the invention is shown. The network 500 comprises a first oscillator 510 and a second oscillator 520. The first oscillator 510 comprises an oscillating element 511 and the second oscillator 520 comprises an oscillating element 521 which may be embodied as a self-heating solid-state phase change device.

[0067] The first oscillator 510 includes a series resistor 512, which is arranged in series with the oscillating element 511. The second oscillator 520 includes a series resistor 522, which is arranged in series with the oscillating element 521. The first oscillator 510 may also include a capacitor 513 arranged in parallel with the series resistor 512. The second oscillator 520 may also include a capacitor 523 arranged in parallel with the series resistor 522. According to an embodiment (not shown), the capacitor may be connected in parallel with the oscillating element so that the oscillating element and the capacitor form a parallel arrangement. In addition, there may be a resistive element connected in series with the parallel arrangement.

[0068] The first series resistor 512 is arranged beside or close to the oscillating element 521, thereby achieving thermal coupling with the oscillating element 521. The heat dissipated by the series resistor 512 of the oscillator 510 affects the oscillator 520, but the series resistor 512 itself is not affected by the oscillator 520 due to its approximately constant resistance over temperature. In addition, the oscillating element 511 and the oscillating element 521 are placed at too large a distance to thermally shock each other. As a result of this arrangement, a unidirectional thermal coupling between the first oscillator 510 and the second oscillator 520 can be achieved.

[0069] Figure 6A network 600 according to another embodiment of the present invention is shown. The network 600 includes a first oscillator 610 and a second oscillator 620. The first oscillator 610 includes an oscillating element 611, and the second oscillator 620 includes an oscillating element 621, which can be embodied as a self-heating solid-state phase change device. For ease of illustration, the first oscillating element 610 and the second oscillating element 621 are shown in a simplified form. The first oscillator 610 and the second oscillator 620 are integrated on a common substrate 630, such as a silicon substrate or a III-V substrate. The network 600 includes a thermal waveguide 640 between the first oscillator 610 and the second oscillator 620. The thermal waveguide 640 can be integrated in the substrate 630. The thermal waveguide 640 includes a thermal diffusivity α thwaveguide The thermal diffusivity of the material is different from that of the substrate thsubstrate This can be used to manipulate or adapt the propagation of thermal waves between the respective oscillating elements of the first oscillator 610 and the second oscillator 620. The corresponding thermal wave propagating through the substrate is shown by the dashed line pattern 631, while the corresponding wave propagating through the thermal waveguide 640 is shown by the dotted line pattern 641. More specifically, the corresponding thermal waves 631 and 641 are only in phase. and Shown at.

[0070] exist Figure 6 In the example, the thermal waveguide 640 includes a thermal diffusivity α thwaveguide >α thsubstrate Therefore η thwaveguide >η Substrate .

[0071] Therefore, the wavelength of the thermal wave 641 within the thermal waveguide 640 is longer than the wavelength of the thermal wave 631 within the substrate 630 .

[0072] Figure 7 A network 700 according to another embodiment of the present invention is shown. The network 700 includes a first oscillator 710 and a second oscillator 720. The first oscillator 710 includes an oscillating element 711, and the second oscillator 720 includes an oscillating element 721, which can be embodied as a self-heating solid-state phase change device. The first oscillator 710 and the second oscillator 720 are integrated on a common substrate 730 (e.g., a silicon substrate or a III-V substrate). The network 700 includes a groove 735 as a thermal separation structure, and the groove 735 is etched into the substrate 730 of the network. The groove 735 is configured to provide thermal isolation between the first oscillator 710 and the second oscillator 720. The groove 735 can be filled with a material with a low thermal diffusivity α to suppress the propagation of thermal waves and achieve non-coupling. This can achieve denser packaging, because heat dissipation from external circuit elements or from parts of the network that are not desired to be thermally coupled can also have parasitic effects and can affect the network in a destructive manner.

[0073] The corresponding wave propagating through the substrate is shown by the dashed line pattern 731.

[0074] According to an embodiment, the coupling strength of the thermal coupling can be increased by replacing the resistor with two or more adjustable resistors in parallel or series. Figure 5 The coupled series resistor 512 with a fixed resistance is shown to operate with only one adjustable resistor coupled to the second oscillator. Figure 8 Such an arrangement is shown. According to an embodiment, the adjustable resistor may be implemented or embodied by a transistor or a memristor or any other element having an adjustable resistance.

[0075] Figure 8 A network 800 according to another embodiment of the present invention is shown. The network 800 comprises a first oscillator 810 and a second oscillator 820. The first oscillator 810 comprises an oscillating element 811 and the second oscillator 820 comprises an oscillating element 821 which may be embodied as a self-heating solid-state phase change device.

[0076] The first oscillator 810 includes a series resistor 812 and a series resistor 813, which are arranged in series with the oscillation element 811. The first oscillator 810 may also include a capacitor 814 arranged in parallel with the series resistor 812. The series resistors 812 and 813 are embodied as adjustable resistors, whose resistances can be adjusted.

[0077] The series resistor 812 is arranged beside or close to the oscillating element 821, thereby achieving thermal coupling with the oscillating element 821. The heat dissipated by the series resistor 812 affects the oscillator 820, but the series resistor 812 itself is not affected by the oscillator 820 because the resistance of the oscillator 820 is approximately constant over temperature. In addition, the oscillating element 811 and the oscillating element 821 are placed at too large a distance to thermally shock each other.

[0078] In the following, it is assumed that the resistor 812 has a resistance R S1,1 , and resistor 813 has a resistance R S1,2 By adjusting resistors 812 and 813 simultaneously, their total resistance R ges1 (R S1,1 , R S1,2 ) remains constant, and R ges1 The energy consumed also remains constant, so the electrical characteristics of the network or circuit are not changed, but the resistor R S1,1 and R S1,2 The energy consumption in R increases in one and decreases in the other. Since only one of the two is coupled to the oscillating element 821, in the example R S1,1In this embodiment, the influence of oscillator 810 on oscillator 820 can be adjusted. In addition, by splitting the series resistance R of oscillator 820 ges2 , the effect of oscillator 820 on oscillator 810 can also be adjusted (the series resistance of oscillator 820 is not in Figure 8 ).

[0079] According to an embodiment, the following coupling strength configurations may generally be achieved.

[0080] Looking at the coupling of the two oscillators, one can select between configurations, for example, one or more of: unidirectional coupling, such that oscillator 810 affects oscillator 820; unidirectional coupling, such that oscillator 820 affects oscillator 810; bidirectional coupling, such that oscillator 810 affects oscillator 820 with a first coupling strength a, and oscillator 820 affects oscillator 810 with a second coupling strength b; and / or no coupling.

[0081] According to an embodiment, the series resistance R of the oscillator ges Can be divided into two resistors R arranged in parallel or in series S1,1 and R S1,2 The arrangement can be such that one of the two resistors has a different distance to the adjacent oscillating element. The total resistance can be set, while the ratio between the two resistors can also be varied independently. This enables variable thermal coupling.

[0082] According to an embodiment, the adjustable resistor may be implemented by a resistance element including a transistor or a memristor.

[0083] Figure 9a 9c shows a network 900 configured to perform adaptive thermal coupling between a first oscillator 910 and a second oscillator 920. The network 900 corresponds to Figure 6 The network 600 shown in FIG. 6A includes a first oscillator 910 and a second oscillator 920. The first oscillator 910 includes an oscillating element 911, and the second oscillator 920 includes an oscillating element 921, which can be embodied as a self-heating solid-state phase change device. For ease of illustration, the second oscillating element 921 is shown in a simplified form. The first oscillator 910 and the second oscillator 920 are integrated on a common substrate 930 (e.g., a silicon substrate or a III-V substrate). The network 900 includes a thermal waveguide 940 between the first oscillator 910 and the second oscillator 920. The thermal waveguide 940 can be integrated in the substrate 930. The thermal waveguide 940 includes a thermal diffusivity α thwaveguide The thermal diffusivity of the material is different from that of the substrate thsubstrate The corresponding wave propagating through the substrate is shown by the dashed line pattern 931, while the corresponding wave propagating through the thermal waveguide 940 is shown by the dotted line pattern 941. More specifically, only in the phase and The corresponding waves 931 and 941 are shown.

[0084] The first oscillator 910 and the second oscillator 920 are arranged to be spaced apart by a constant distance d.

[0085] The network 900 is configured to perform adaptive thermal coupling, in particular by adapting the oscillation frequency of one or more oscillators of the network 900 and thereby changing the corresponding thermal coupling mode.

[0086] More specifically, Figure 9a shows a negative coupling, Figure 9b A positive coupling is shown, and FIG. 9c shows no coupling.

[0087] Thermal coupling modes, such as positive coupling (driving the oscillator to ), negative coupling (driving the oscillator to ) or uncoupled (arbitrary phase, amplitude ≈ 0, no interaction between the oscillators) is determined by three parameters: the distance d between the two oscillators, the effective thermal diffusivity α of the material coupling the oscillators and the frequency f of the oscillation. Two of these parameters are usually set during manufacturing, namely the distance d and the effective thermal diffusivity α, and are therefore kept constant during operation of the network. By means of frequency tuning, the mode of thermal coupling can be changed from negative to positive by lowering the frequency and from negative to no to non-coupling by increasing the oscillation frequency. According to an embodiment, this change of frequency can be achieved by changing the circuit parameters within the network, more specifically the circuit parameters of the oscillators involved. According to an embodiment, the change of frequency can be achieved by locally or globally changing the temperature of the substrate of the corresponding network or chip.

[0088] Reference now Figure 9a , negative coupling can be achieved by choosing the distance d so that where ω * =2πf * And f * is the frequency of the first oscillator 910 for negative coupling, which is selected to be between the maximum adjustable frequency and the minimum adjustable frequency of the oscillator 910 (f min <f * <f max ).

[0089] refer to Figure 9b , positive coupling can be achieved by selecting the angular frequency v1 of the oscillator 910 to be smaller than the corresponding frequency ω* of the negative coupling: ω1<ω*.

[0090] Referring to FIG. 9 c , decoupling can be achieved by selecting the angular frequency ω2 of the oscillator 910 to be greater than the corresponding frequency ω* of the negative coupling: ω2>ω*.

[0091] Therefore, the amplitude of the thermal wave at the second oscillator 920 will be very low.

[0092] According to an embodiment, instead of operating the two oscillators at the same frequency, the oscillators can also be coupled at different or the same harmonics (integer multiples of the frequency f).

[0093] Fig.10 The method steps of the method according to the embodiment of the present invention are shown. For the method steps, specific reference is made to the network 900 of FIG. 9 .

[0094] At step 1010, the method starts.

[0095] At step 1020, the control logic of the network 900 checks which coupling mode it should operate in and obtains the desired coupling mode.

[0096] At step 1030, the frequency of the respective oscillator is adjusted to operate in the desired coupling mode.

[0097] Then, at step 1040, the network 900 controls the phase of the oscillator by thermal coupling via the thermal link.

[0098] The present invention may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium (or medium) having computer-readable program instructions thereon for causing a processor to perform various aspects of the present invention.

[0099] The present invention may be embodied as a computer program product for operating a network (eg, networks 100 to 900 described above).

[0100] A computer-readable storage medium may be a tangible device that can retain and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device (such as a punched card or a raised structure in a groove on which instructions are recorded), and any suitable combination of the foregoing. As used herein, a computer-readable storage medium should not be interpreted as a temporary signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagated through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0101] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded to an external computer or external storage device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network). The network can include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in a computer-readable storage medium in the corresponding computing / processing device.

[0102] The computer-readable program instructions for performing the operation of the present invention can be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional process programming languages ​​such as "C" programming language or similar programming languages. The computer-readable program instructions can be executed completely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer, or completely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, by using the Internet of an Internet service provider). In certain embodiments, the electronic circuit including, for example, a programmable logic circuit, a field programmable gate array (FPGA) or a programmable logic array (PLA) can execute the computer-readable program instructions to personalize the electronic circuit by utilizing the state information of the computer-readable program instructions, so as to perform various aspects of the present invention.

[0103] Various aspects of the present invention are described herein with reference to the flow charts and / or block diagrams of the methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each frame of the flow chart diagram and / or block diagram and the combination of frames in the flow chart diagram and / or block diagram can be implemented by computer-readable program instructions.

[0104] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the functions / actions specified in one or more boxes of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium, which can instruct a computer, a programmable data processing device, and / or other equipment to function in a specific manner, so that the computer-readable storage medium having the instructions stored therein includes an article of manufacture, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes of the flowchart and / or block diagram.

[0105] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device, so that a series of operational steps are performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, so that the instructions executed on the computer, other programmable apparatus, or other device implement the functions / actions specified in one or more boxes of the flowchart and / or block diagram.

[0106] The flow charts and block diagrams in the accompanying drawings illustrate the architecture, functions and operations of possible implementations of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, segment or part of an instruction, which includes one or more executable instructions for implementing a specified logical function. In some alternative embodiments, the functions marked in the box may not occur in the order marked in the figure. For example, the two boxes shown in succession can actually be executed substantially simultaneously, or these boxes can sometimes be executed in reverse order, depending on the functions involved. It will also be noted that each box illustrated in the block diagram and / or flow chart and the combination of boxes in the block diagram and / or flow chart can be implemented by a system based on dedicated hardware that performs a specified function or action or performs a combination of dedicated hardware and computer instructions.

[0107] The description of various embodiments of the present invention has been presented for the purpose of illustration, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, practical applications, or technical improvements over technologies found in the marketplace, or to enable those of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A network comprising a plurality of oscillators, wherein the network is configured to control the phases of the plurality of oscillators by thermal coupling via a thermal link.

2. The network of claim 1, wherein the thermal coupling comprises an anti-phase coupling. The network of claim 1 , wherein the thermal coupling comprises an in-phase coupling.

4. The network of claim 1, wherein the network comprises a plurality of electrical links for electrically coupling the plurality of oscillators.

5. The network according to claim 1, wherein: The network is a neural network; and The plurality of oscillators form an oscillatory neural network.

6. The network of claim 1, wherein the plurality of oscillators comprises a first oscillator and a second oscillator, wherein the second oscillator is arranged within an anti-phase coupling region of the first oscillator.

7. The network of claim 1, wherein the plurality of oscillators comprises a first oscillator, a second oscillator, and a third oscillator, wherein the first oscillator, the second oscillator, and the third oscillator are all arranged in an anti-phase coupling region relative to each other.

8. The network of claim 1, wherein each oscillator of the plurality of oscillators is implemented as a relaxation oscillator.

9. The network of claim 1, wherein each oscillator of the plurality of oscillators comprises a self-heating solid-state phase change device comprising a phase change material having a first phase and a second phase.

10. The network of claim 9, wherein the first phase state is a low impedance state and the second phase state is a high impedance state.

11. The network of claim 9, wherein the solid phase change material is selected from the group consisting of VO2, V4O7, V6O11, V2O3, V6O13, V5O9, VO, V8O15, NbO2, Ti2O3, LaCoO3, Ti3O5, SmNiO3, NdNiO3, PrNiO3 and Fe3O4.

12. The network of claim 9 , wherein the plurality of oscillators comprises a first oscillator and a second oscillator, the first oscillator comprising a first series arrangement of a first self-heating phase change device and a first series resistor, the second oscillator comprising a second series arrangement of a second self-heating phase change device and a second series resistor, wherein the first series resistor is thermally coupled to the second self-heating phase change device, thereby achieving unidirectional thermal coupling between the first oscillator and the second oscillator.

13. The network of claim 1 further comprising one or more thermal waveguides for facilitating said thermal coupling.

14. The network of claim 1, further comprising one or more thermal separation structures etched into a substrate of the network, the one or more thermal separation structures configured to provide thermal isolation between two or more oscillators of the plurality of oscillators.

15. The network of claim 1, wherein the network is configured to perform adaptive thermal coupling between two or more of the plurality of oscillators by adjusting an oscillation frequency of one or more of the plurality of oscillators, thereby changing a thermal coupling pattern.

16. The network of claim 15, wherein adjusting the oscillation frequency comprises changing one or more parameters of electrical components of the network.

17. The network of claim 15, wherein adjusting the oscillation frequency comprises changing a local or global temperature of a substrate of the network.

18. The network of claim 1, wherein one or more of the plurality of oscillators comprises two or more adjustable resistors, wherein only one of the two or more adjustable resistors is thermally coupled to another oscillator of the plurality of oscillators.

19. A method for operating a network comprising a plurality of oscillators, the method comprising controlling the phases of the plurality of oscillators by thermal coupling via a thermal link.

20. A computer program product for operating a network, the network comprising a plurality of oscillators and a plurality of hot links, the computer program product comprising a computer readable storage medium having program instructions embodied therein, the program instructions executable by the network to perform a method comprising: The phases of the plurality of oscillators are controlled by thermal coupling via a thermal link.

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