WO2018186826A1

WO2018186826A1 - Optical transduction for magneto-electric spin orbit logic

Info

Publication number: WO2018186826A1
Application number: PCT/US2017/025736
Authority: WO
Inventors: Sasikanth Manipatruni; Dmitri E. Nikonov; Ian A. Young
Original assignee: Intel Corporation
Priority date: 2017-04-03
Filing date: 2017-04-03
Publication date: 2018-10-11

Abstract

Embodiments are generally directed to optical transduction for Magneto-Electric Spin Orbit (MESO) logic. An embodiment of an apparatus includes an optical waveguide to receive an optical input; and an optical to electrical transducer, the optical to electrical transducer including an optical to charge converter, a charge to magnetic state converter, and a magnetic state to charge converter.

Description

OPTICAL TRANSDUCTION FOR MAGNETO-ELECTRIC SPIN ORBIT LOGIC

TECHNICAL FIELD

Embodiments described herein generally relate to the field of electronic devices and, more particularly, optical transduction for Magneto-Electric Spin Orbit (MESO) logic. BACKGROUND

With electronics approaching the nanometer scale, a scalable spintronic logic device that operates via spin-orbit transduction combined with magneto-electric switching has been developed as a technology to move beyond Complementary Metal Oxide Semiconductor (CMOS) computing. The Magneto-Electric Spin Orbit (MESO) logic enables the continued scaling of logic device to smaller scales. Spintronic logic can enable energy and computational efficiency by utilizing a new state variable for computation.

However, leading spintronic logic options suffer from high energy/switching due to the spin transfer torque induced by charge. Large write currents (> 10- 100 μ A/bit) produce high joule heat dissipation, and the slow switching characteristic of spin current induced switching increases large energy-delay for spin logic using spin currents.

Such issues regarding MESO logic operation may have a significant impact on the design and operation of elements including long range interconnects. Long range interconnects play a critical role in microprocessors and electronics for data transfer from the memory to core, between cores, and from off-chip components to on chip components.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments described here are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements.

Figure 1A is an illustration of a system for optical signal transmission utilizing spin logic elements according to an embodiment;

Figure IB is an illustration of elements of a spin logic device with optical transducer according to an embodiment;

Figure 2 is an illustration of a Magneto-Electric Spin Orbit (MESO) logic device including an optical detector and optical to electrical transducer element according to an embodiment;

Figure 3 is an illustration of the photoelectric effect of a magneto-electric medium for conversion according to an embodiment; Figures 4A and 4B illustrate voltage and current in response to light intensity in an optical signal detection for a spin orbit logic device according to an embodiment;

Figure 4C illustrates a switching of the phase for a spin orbit logic device according to an embodiment;

Figure 5 is a listing of multiferroics with photoelectric effect;

Figure 6 illustrates the spectrum of a semiconductor laser utilized in generation of an optical signal according to an embodiment;

Figure 7 illustrates the absorption spectrum for multiferroic bismuth ferrite;

Figure 8 is a flowchart to illustrate a process for operation of a spin logic device with optical transduction according to an embodiment; and

Figure 9 is an illustration of a system including spin logic elements providing optical transduction according to an embodiment.

DETAILED DESCRIPTION

Embodiments described herein are generally directed to optical transduction for

Magneto-Electric Spin Orbit (MESO) logic.

"Magneto-Electric Spin Orbit logic" or "MESO logic" refers to logic utilizing a spintronic logic device that operates via spin-orbit transduction combined with magneto-electric switching, the MESO logic utilizing magnetic state (or spin state) for logical operation.

In MESO logic, there is commonly high energy/switching due to the spin transfer torque induced by charge. The large write currents produce high joule heat dissipation, and the slow switching characteristic of spin current induced switching increases large energy-delay for spin logic using spin currents.

In some embodiments, to address limitations regarding spin logic switching, optical to electric transduction is implemented to provide a reduction in the switching energy costs. In some embodiments, an optical to electrical transducer is embedded in a magneto-electric spin orbitronics logic device (also referred to herein as a spin logic device). In some embodiments, the optical to electrical transducer provides a combination of physical phenomena for "optical to charge" conversion, and "charge to magnetic state conversion".

In some embodiments, a system may include an optical source including a semiconductor laser to generate an optical signal, including, for example, a signal for long range interconnects in a microelectronic circuit. In some embodiments, the optical signal is received by a spin logic device including an optical to electrical transducer.

In some embodiments, an optical to electrical transducer element provides the following conversion: (1) Optical to charge conversion is achieved via photo-electric effect in the magneto- electric medium.

(2) Charge to magnetic state conversion is achieved via magneto-electric switching mediated by voltage applied to a magneto-electric multiferroic. A multiferroic is general is a material exhibiting more than one primary ferroic order parameter simultaneously.

(3) Spin to charge conversion is achieved via the Rashba-Edelstein effect, wherein an injected spin current produces a charge current.

In some embodiments, the optical to electric conversion may be implemented to provide the following:

(1) Implementation in interconnects, such as long range interconnects, to interface with

Magneto-electric logic, while requiring low energy per bit.

(2) High speed operation of the optical detector (1-100 ps (picoseconds)) via the use of magneto-electric switching.

(3) Reduced switching energy as a result of the reduced switching time.

(4) Efficient spin to charge conversion using the Edelstein-Rashba effect.

(5) Efficient charge to magnetic switching using magneto-electric effect.

Figure 1A is an illustration of a system for optical signal transmission utilizing spin logic elements according to an embodiment. In some embodiments, a signal generator element 102 in a microelectronic system is operable to generate a signal for transmission. In some

embodiments, the signal may include, but is not limited to, a signal for long range interconnect transfer, for example, from memory to processor core, between processor cores, or from off-chip components to on chip components. In some embodiments, the signal is provided to an optical source 104, such as an element including a semiconductor laser, to generate an optical signal. The optical signal may be transmitted via an optical channel 106, such as a waveguide or other element.

In some embodiments, the optical signal is received as an input 108 to a spin logic device 110. In some embodiments, the spin logic device 110 includes an optical to electrical transducer 120 to detect the optical signal and covert such signal to an electrical signal. The spin logic device 110 and optical to electrical transducer are described in more depth with regard to Figure IB.

In some embodiments, the spin logic device 110 produces a charge output 160 for use in the system. Figure IB is an illustration of elements of a spin logic device with optical to electrical transducer according to an embodiment. In some embodiments, a spin logic device with optical transduction 110 includes the following elements:

(a) An optical waveguide 112, the optical waveguide being operable to receive an optical signal received from an optical source, which may include a semiconductor laser.

(b) An optical to electrical transducer 120 to detect and convert optical signals for the spin logic device 110. The electrical transducer 120 includes:

(1) An optical to charge converter 122, wherein the optical to charge converter including a magneto-electric multiferroic material with photo-electric effect.

(2) Charge to magnetic state converter 124, wherein charge to magnetic state conversion is achieved via magneto-electric switching that is mediated by a voltage applied to the magneto- electric multiferroic.

(3) Spin to charge converter 126, wherein spin to charge conversion includes injection by a nanomagnet injector of a spin current into a first injection stack.

(c) A charge interconnect 130, such as a copper channel in the spin logic device 110.

(d) Charge detector and converter mechanism 140 to convert charge to magnetic state. In some embodiments, the detection and conversion of a charge signal includes:

(1) The build-up of charge on a magneto-electric capacitor 142, the capacitor including a magneto-electric dielectric.

(2) Switching on a nanomagnet detector 144 to generate a magnetic state, the switching being in response to the charge on the magneto-electric capacitor.

(e) Magnetic state to charge converter 150, wherein the magnetic state to charge conversion includes injection by nanomagnet detector of a spin current into a second injection stack.

Figure 2 is an illustration of a Magneto-Electric Spin Orbit (MESO) logic device including an optical detector and optical to electrical transducer element according to an embodiment. As illustrated in Figure 2, an optical to electrical transducer is embedded into a MESO Logic Device that provides magneto-electric switching.

The spin orbit logic device 200 includes two nanomagnets, a first nanomagnet 210 (referred to herein as a nanomagnet injector) and a second nanomagnet 240 (referred to herein as a nanomagnet detector) sharing a copper channel 230 acting as a charge interconnect.

In some embodiments, an incoming optical waveguide 205 is to carry optical information to the spin orbit logic device 200. The optical information carried by the optical waveguide 205 may be coded as, for example, either non-return to zero format (NRZ, wherein a signal does not return to zero between signal pulses) or return to zero (RZ, wherein a signal does return to zero between signal pulses) format.

In some embodiments, the optical waveguide 205 is coupled to a multiferroic with photoelectric effect 225. The multiferroic is a photoactive (i.e. a material with photo-electric effect) magneto-electric medium and may include a material provided in Figure 5. In some

embodiments, the multiferroic 225 is a material with highly reduced switching voltage. A multiferroic with highly reduced switching voltage may be achieved by (1) thickness scaling; (2) stoichiometry and vacancy control; and (3) doping with La (Lanthanum), Ce (Cerium), or Ca (Calcium). In some embodiments, domain walls are optionally included for lowering the carrier lifetime to increase the speed of the device and collection of photo-carriers to the electrodes.

In some embodiments, with regard to the optical detection mechanism and optical to charge conversion, the optical detection mechanism is mediated by generation of electron-hole pairs that are swept in the internal electric field due to inbuilt polarization of the multiferroic 225. The conduction of the electrons may be mediated via the following:

(a) Tunneling;

(b) Hopping conduction; or

(c) Conduction at the ferro-electric domain walls with charge accumulation.

In some embodiments, charge to magnetic state conversion is achieved via magneto- electric switching mediated by voltage applied to the magneto-electric multiferroic 225, resulting in the magnetic state of the nanomagnet inj ector 210.

In some embodiments, as injection mechanism for magnetic state to charge conversion in the spin orbit logic device 200 is as follows:

The nanomagnet injector 210 is to inject a spin current into a high spin orbit coupling material stack. Because of the intrinsic polarization of the nanomagnetic material, a spin polarized current is injected into the injection stack. As illustrated in Figure 2, the injection stack includes a high spin orbit interaction material 215, such as Ag/Bi (Silver/Bismuth), and a 2D interfacial electron gas or a high Spin Hall Effect (SHE) material such as Ta/W/Pt

(Tantalum/Tungsten/Platinum) 220 with a silver/copper spacer between 215 and 220.

The spin-orbit mechanism responsible for spin to charge conversion is described by Rashba effect in a 2D electron gases. The Rashba Hamiltonian (energy) of spin polarized electrons in a 2D gas is described by:

H_R = a_R(k x ζ). σ [1] where (¾is the Rashba coefficient, 'k' is the operator of momentum of electrons, z is a unit vector perpendicular to the 2D electron gas, and σ is the operator of spin of electrons. Spin polarized electrons with direction of polarization in-plane (in the XY plane) observe an effective magnetic field dependent on the spin direction:

B(k)= _B (k x z) [2] where ^_sis the Bohr's magneton.

This results in the generation of a charge current in the interconnect proportional to the injected current. The spin-orbit interaction (Inverse Rashba-Edelstein Effect (IREE)) produces a charge current in the interconnect:

I_c = ½ ½ [3]

Alternatively, an Inverse Spin Hall Effect based injector stack (with Ag/SHE metal) produces a charge current:

_ ®SHEtsheIs r

Both IREE and ISHE effects produce spin to charge current conversion between 0.1 with existing materials at 10 nm magnet width. For scaled nanomagnets (5 nm width), the spin to charge current conversion efficiency can be between 1 - 2.5.

The net conversion of the drive current to magnetization dependent charge current is given by :

For IREE

^{Ic = ±} ^ ^[6]

For ISHE

In some embodiments, the spin logic device 200 further includes a charge detection and conversion mechanism is as follows: The charge current carried by the charge interconnect 230 produces a voltage on a capacitor comprising of the ferromagnet elements of the nanomagnet 240 with a magneto-electric (ME) material dielectric 245. As the charge accumulates on the magneto-electric capacitor a strong magneto-electric interaction causes the switching of the nanomagnet detector 240. Typical magneto-electric dielectric materials include intrinsic multiferroic materials and multi-phase multiferroic materials.

In some embodiments, the switching threshold charge for multiferroic switching is an illustrated in Figures 4 A, 4B, and 4C.

In some embodiments, the spin orbit logic device 200 further provides magnetic state conversion to a charge output, Icharge (OUT) 260, utilizing an injection mechanism for spin to charge conversion in the spin orbit logic device 200. The nanomagnet detector 240 is to inject a spin current into a second high spin orbit coupling material stack, the second injection stack includes high spin orbit interaction material 250, such as Ag/Bi with 2D interfacial electron gas or a high Spin Hall Effect (SHE) material such as Ta/W/Pt (Tantalum, Tungsten, or Platinum) 255 with a silver/copper spacer between 250 and 255.

The proposed spin orbit logic device 200 provides logic repeatability and unidirectional logic propagation. The spin orbit logic device 200 is illustrated as a logic inverter or repeater in Figure 2, but embodiments are not limited to this logical construction, and may include other spin logic devices. The energy to regenerate the logic signal is derived from the power supply driving the charge current during the injector operation.

The logic repeater operation works by injection of a spin current from the nanomagnet injector 210. For negative applied voltages to the nanomagnet injector 210, a spin current polarized in the same direction as the nanomagnet is injected into the high SOC (Spin Orbit Coupling) region. The SOC effects produce a charge current proportional to the injected spin current. The injected charge current charges a magnetoelectric stack producing a large effective magnetic field on the detector free layer.

In some embodiments, the logic inverter operation by the spin orbit logic device 200 operates by injection of a spin current from the nanomagnet 240 with a +Vdd power supply. The injected charge current charges the magnetoelectric stack 250-255 with opposite polarity, producing a large effective magnetic field on the detector free layer.

Figure 3 is an illustration of the photoelectric effect of a magneto-electric medium for conversion according to an embodiment. Figure 3 illustrates the effect at for the charge to magnetic state from the multiferroic material 225 to the nanomagnet injector 210. In some embodiments, charge to magnetic state conversion is achieved via magnetoelectric switching mediated by voltage applied to the magnetoelectric multiferroic 225.

Figures 4A and 4B illustrate voltage and current in response to light intensity in an optical signal detection for a spin orbit logic device according to an embodiment. Specifically, Figure 4A illustrates Voc in response to light intensity, wherein polarization down results in a positive voltage and polarization down results in a negative voltage. Figure 4B illustrates Isc in response to light intensity, wherein polarization down results in a positive current and polarization down results in a negative current.

Figure 4C illustrates a switching of the phase for a spin orbit logic device according to an embodiment. As illustrated, upon a voltage reaching a certain level the phase response is to shift 180 degrees (from 0 degrees to 180 degrees and back). Thus, upon the voltage reaching approximately +150 mV the phase shifts from 0 degrees to 180, and upon the voltage reaching approximately -150 mV the phase shifts from 180 degrees to 0 degrees.

Figure 5 is a listing of multiferroics with photo-electric effect. In some embodiments, the multiferroic 225 of the spin orbit logic device illustrated in Figure 2 is a material chosen from the materials present in Figure 5.

In a particular embodiment, a multiferroic for implementation in an optical transducer of a spin logic device may include, but is not limited to, bismuth ferrite (BFO (BiFe03)).

Figure 6 illustrates the spectrum of a semiconductor laser utilized in generation of an optical signal according to an embodiment. In some embodiments, the laser is a laser, such as a GaN (Gallium Nitride) laser, that is engineered for photoemission at a wavelength to match the spectrum of a multiferroic material, such as being engineered to emit at a highest absorbing part of the spectrum of the multiferroic material, such as the spectrum of BFO as illustrated in Figure 7.

Figure 7 illustrates the absorption spectrum for multiferroic bismuth ferrite. The responsivity of bismuth ferrite (BFO (BiFe03)) is illustrated, which illustrates the wavelength of choice for BFO being between 300 nm and 400 nm. The optical source may be a semiconductor laser, such as a GaN laser engineered for photoemission at a high absorbing part of the BFO spectrum.

Figure 8 is a flowchart to illustrate a process for operation of a spin logic device with optical transduction according to an embodiment. In some embodiments, a process 800 may include the following:

802: Receive an optical signal at a spin logic device from an optical source, which may include a semiconductor laser.

804: Convert optical signals to charge utilizing magneto-electric multiferroic material with photo-electric effect.

806: Convert charge to spin/magnetic state, including magneto-electric switching mediated by a voltage applied to the magneto-electric multiferroic.

808: Convert spin/magnetic state to charge, wherein the magnetic state to charge conversion includes injection of a spin current into a first injection stack.

810: Transmit charge current via a charge interconnect.

812: Detect the charge signal and convert the charge signal to a spin/magnetic state.

814: Convert spin/magnetic state to charge, including injection of spin current into a second injection stack.

816: Output of change current. Figure 9 is an illustration of a system including spin logic elements providing optical transduction according to an embodiment. In this illustration, certain standard and well-known components that are not germane to the present description are not shown. The system may include a SoC (System on Chip) combining multiple elements on a single chip.

In some embodiments, a system 900 includes MESO logic elements 980, the MESO logic elements including one or more spin logic devices 982 that include optical transduction. In some embodiments, the spin logic devices 982 include devices as illustrated in Figure IB and Figure 2. In some embodiments, one or more spin logic devices are utilized in connection with an interconnect, such as a long range interconnect. However, embodiments are limited to this use implementation.

In some embodiments, the system 900 may include a processing means such as one or more processors 910 coupled to one or more buses or interconnects, shown in general as bus 905. The processors 910 may comprise one or more physical processors and one or more logical processors. In some embodiments, the processors may include one or more general-purpose processors or special-purpose processors. In some embodiments, one or more processors include multiple cores.

The bus 905 is a communication means for transmission of data. The bus 905 is illustrated as a single bus for simplicity, but may represent multiple different interconnects or buses and the component connections to such interconnects or buses may vary. The bus 905 shown in Figure 9 is an abstraction that represents any one or more separate physical buses, point-to-point connections, or both connected by appropriate bridges, adapters, or controllers.

In some embodiments, the system 900 further comprises a random access memory (RAM) or other dynamic storage device or element as a main memory 915 for storing

information and instructions to be executed by the processors 910. Main memory 915 may include, but is not limited to, dynamic random access memory (DRAM).

The system 900 also may comprise a non-volatile memory 920; and a read only memory (ROM) 935 or other static storage device for storing static information and instructions for the processors 910.

In some embodiments, the system 900 includes one or more transmitters or receivers 945 coupled to the bus 905. In some embodiments, the system 900 may include one or more antennas 950, such as dipole or monopole antennae, for the transmission and reception of data via wireless communication using a wireless transmitter, receiver, or both, and one or more ports 955 for the transmission and reception of data via wired communications. Wireless communication includes, but is not limited to, Wi-Fi, Bluetooth™, near field communication, and other wireless communication standards.

The system 900 may also comprise a battery or other power source 960, which may include a solar cell, a fuel cell, a charged capacitor, near field inductive coupling, or other system or device for providing or generating power in the system 900. The power provided by the power source 960 may be distributed as required to elements of the system 900.

In some embodiments, an apparatus includes an optical waveguide to receive an optical input; and an optical to electrical transducer, the optical to electrical transducer including an optical to charge converter, a charge to magnetic state converter, and a magnetic state to charge converter.

In some embodiments, the optical to charge converter includes a multiferroic material with photoelectric effect.

In some embodiments, the charge to magnetic state converter is to be mediated by a voltage applied to the multiferroic material.

In some embodiments, multiferroic material includes bismuth ferrite (BiFe03).

In some embodiments, the magnetic state to charge converter includes a first nanomagnet to receive a magnetic state from the charge to magnetic state converter.

In some embodiments, the magnetic state to charge converter further includes a first injection stack, the first nanomagnet to inject a first spin current into the first injection stack.

In some embodiments, the first injection stack includes a high spin orbit interaction material.

In some embodiments, the first injection stack includes one of a 2D interfacial electron gas or a high Spin Hall Effect (SHE) material.

In some embodiments, a spin logic device includes an optical waveguide to receive an optical input; an optical to electrical transducer, the optical to electrical transducer including an optical to charge converter, a charge to magnetic state converter, and a first magnetic state to charge converter; a charge interconnect coupled with the optical to electrical transducer; a charge detector and converter mechanism to convert charge to magnetic state; and a second magnetic state to charge converter to generate a charge output.

In some embodiments, the charge to magnetic state converter is to be mediated by a voltage applied to the multiferroic material. In some embodiments, the first magnetic state to charge converter includes a first nanomagnet to receive a magnetic state from the charge to magnetic state converter.

In some embodiments, the first magnetic state to charge converter further includes a first injection stack, the first nanomagnet to inject a first spin current into the first injection stack.

In some embodiments, the charge detector and converter mechanism includes a magneto- electric capacitor to receive charge from the charge interconnect.

In some embodiments, the second magnetic state to charge converter includes a second nanomagnet to receive a magnetic state from the magneto-electric capacitor.

In some embodiments, the second magnetic state to charge converter further includes a second injection stack, the second nanomagnet to inject a second spin current into the second injection stack.

In some embodiments, the spin logic device is configured as a logic inverter or a logic repeater.

In some embodiments, a system includes a processor to process data, the processor including a plurality of cores; a dynamic random access memory (DRAM) to store data; and one or more Magneto-Electric Spin Orbit (MESO) logic elements including a first logic device. In some embodiments, wherein the first logic device includes an optical waveguide to receive an optical input; and an optical to electrical transducer, the optical to electrical transducer including an optical to charge converter, a charge to magnetic state converter, and a magnetic state to charge converter.

In some embodiments, the system further includes an interconnect, the interconnect to provide an optical signal to the first logic device.

In some embodiments, the interconnect is one of an interconnect between the DRAM and a core of the processor or between a first cores and a second core of the processor.

In some embodiments, the system further includes a laser to generate the optical signal, the laser being engineered for photoemission at a wavelength to match a spectrum of the multiferroic material. In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the described embodiments. It will be apparent, however, to one skilled in the art that embodiments may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form. There may be intermediate structure between illustrated components. The components described or illustrated herein may have additional inputs or outputs that are not illustrated or described.

Various embodiments may include various processes. These processes may be performed by hardware components or may be embodied in computer program or machine- executable instructions, which may be used to cause a general-purpose or special-purpose processor or logic circuits programmed with the instructions to perform the processes.

Alternatively, the processes may be performed by a combination of hardware and software.

Portions of various embodiments may be provided as a computer program product, which may include a computer-readable medium having stored thereon computer program instructions, which may be used to program a computer (or other electronic devices) for execution by one or more processors to perform a process according to certain embodiments. The computer-readable medium may include, but is not limited to, magnetic disks, optical disks, read-only memory (ROM), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically-erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or other type of computer-readable medium suitable for storing electronic instructions. Moreover, embodiments may also be downloaded as a computer program product, wherein the program may be transferred from a remote computer to a requesting computer.

Many of the methods are described in their most basic form, but processes can be added to or deleted from any of the methods and information can be added or subtracted from any of the described messages without departing from the basic scope of the present embodiments. It will be apparent to those skilled in the art that many further modifications and adaptations can be made. The particular embodiments are not provided to limit the concept but to illustrate it. The scope of the embodiments is not to be determined by the specific examples provided above but only by the claims below.

If it is said that an element "A" is coupled to or with element "B," element A may be directly coupled to element B or be indirectly coupled through, for example, element C. When the specification or claims state that a component, feature, structure, process, or characteristic A "causes" a component, feature, structure, process, or characteristic B, it means that "A" is at least a partial cause of "B" but that there may also be at least one other component, feature, structure, process, or characteristic that assists in causing "B." If the specification indicates that a component, feature, structure, process, or characteristic "may", "might", or "could" be included, that particular component, feature, structure, process, or characteristic is not required to be included. If the specification or claim refers to "a" or "an" element, this does not mean there is only one of the described elements.

An embodiment is an implementation or example. Reference in the specification to "an embodiment," "one embodiment," "some embodiments," or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments. The various appearances of "an embodiment," "one embodiment," or "some embodiments" are not necessarily all referring to the same embodiments. It should be appreciated that in the foregoing description of exemplary embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various novel aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed embodiments requires more features than are expressly recited in each claim. Rather, as the following claims reflect, novel aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims are hereby expressly incorporated into this description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMS What is claimed is:

1. An apparatus comprising:

an optical waveguide to receive an optical input; and

an optical to electrical transducer, the optical to electrical transducer including:

an optical to charge converter,

a charge to magnetic state converter, and

a magnetic state to charge converter.

2. The apparatus of claim 1, wherein the optical to charge converter includes a multiferroic material with photoelectric effect.

3. The apparatus of claim 2, wherein the charge to magnetic state converter is to be mediated by a voltage applied to the multiferroic material.

4. The apparatus of claim 2, wherein multiferroic material includes bismuth ferrite

(BiFe03).

5. The apparatus of claim 1, wherein the magnetic state to charge converter includes a first nanomagnet to receive a magnetic state from the charge to magnetic state converter.

6. The apparatus of claim 5, wherein the magnetic state to charge converter further includes a first injection stack, the first nanomagnet to inject a first spin current into the first injection stack.

7. The apparatus of claim 6, wherein the first injection stack includes a high spin orbit interaction material.

8 The apparatus of claim 6, wherein the first injection stack includes one of a 2D interfacial electron gas or a high Spin Hall Effect (SHE) material.

9. A spin logic device compri

an optical waveguide to receive an optical input;

an optical to charge converter,

a charge to magnetic state converter, and

a first magnetic state to charge converter;

a charge interconnect coupled with the optical to electrical transducer;

a charge detector and converter mechanism to convert charge to magnetic state; and a second magnetic state to charge converter to generate a charge output.

10. The spin logic device of claim 9, wherein the optical to charge converter includes a multiferroic material with photoelectric effect.

11. The spin logic device of claim 10, wherein the charge to magnetic state converter is to be mediated by a voltage applied to the multiferroic material.

12. The spin logic device of claim 9, wherein the first magnetic state to charge converter includes a first nanomagnet to receive a magnetic state from the charge to magnetic state converter.

13. The spin logic device of claim 12, wherein the first magnetic state to charge converter further includes a first injection stack, the first nanomagnet to inject a first spin current into the first injection stack.

14. The spin logic device of claim 9, wherein the charge detector and converter mechanism includes a magneto-electric capacitor to receive charge from the charge interconnect.

15. The spin logic device of claim 14, wherein the second magnetic state to charge converter includes a second nanomagnet to receive a magnetic state from the magneto-electric capacitor.

16. The spin logic device of claim 15, wherein the second magnetic state to charge converter further includes a second injection stack, the second nanomagnet to inject a second spin current into the second injection stack.

17. The spin logic device of claim 9, wherein the spin logic device is configured as a logic inverter or a logic repeater.

18. A system comprising:

a processor to process data, the processor including a plurality of cores;

a dynamic random access memory (DRAM) to store data; and

one or more Magneto-Electric Spin Orbit (MESO) logic elements including a first logic device;

wherein the first logic device includes:

an optical waveguide to receive an optical input; and

an optical to electrical transducer, the optical to electrical transducer including an optical to charge converter,

a charge to magnetic state converter, and

a magnetic state to charge converter.

19. The system of claim 18, wherein the optical to charge converter includes a multiferroic material with photoelectric effect.

20. The system of claim 19, wherein the magnetic state to charge converter includes a first nanomagnet to receive a magnetic state from the charge to magnetic state converter.

21. The system of claim 20, wherein the magnetic state to charge converter further includes a first injection stack, the first nanomagnet to inject a first spin current into the first injection stack.

22. The system of claim 20, further comprising an interconnect, the interconnect to provide an optical signal to the first logic device.

23. The system of claim 22, wherein the interconnect is one of an interconnect between the DRAM and a core of the processor or between a first cores and a second core of the processor.

24. The system of claim 22, wherein further comprising a laser to generate the optical signal, the laser being engineered for photoemission at a wavelength to match a spectrum of the multiferroic material.