Provided are magnetoresistance effect element and a Heusler alloy in which an amount of energy required to rotate magnetization can be reduced. The magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy in which a portion of elements of an alloy represented by Co.sub.2Fe.sub.αZ.sub.β is substituted with a substitution element, in which Z is one or more elements selected from the group consisting of Mn, Cr, Al, Si, Ga, Ge, and Sn, α and β satisfy 2.3≤α+β, α<β, and 0.5<α<1.9, and the substitution element is an element different from the Z element and has a smaller magnetic moment than Co.

Multidrop optical connections are used for an optical memory module. Multiple buffer integrated circuits on a module each receive information from the host system using different wavelengths of light transmitted on the same waveguide. Multiple buffer integrated circuits each transmit information back to the CPU using different wavelengths of light transmitted on another waveguide. Wavelength resonant ring couplers disposed on the buffer integrated circuits are used to separate the wavelength being received by a particular buffer integrated circuit from the wavelengths of light destined for other buffer integrated circuits on the same waveguide. Wavelength resonant ring modulators also disposed on the buffer integrated circuits modulate specific wavelengths of light unique to each buffer integrated circuit to transmit information to the CPU.

Multidrop optical connections are used for an optical memory module. Multiple buffer integrated circuits on a module each receive information from the host system using different wavelengths of light transmitted on the same waveguide. Multiple buffer integrated circuits each transmit information back to the CPU using different wavelengths of light transmitted on another waveguide. Wavelength resonant ring couplers disposed on the buffer integrated circuits are used to separate the wavelength being received by a particular buffer integrated circuit from the wavelengths of light destined for other buffer integrated circuits on the same waveguide. Wavelength resonant ring modulators also disposed on the buffer integrated circuits modulate specific wavelengths of light unique to each buffer integrated circuit to transmit information to the CPU.

Example memory devices and example methods for using memory devices are described. An example memory device may include a first electrical bitline, a second electrical bitline, a bitcell, and an optical waveguide wordline. The bitcell is configured to store a bit value and includes storage circuitry and a pair of light-effect transistor access devices. The storage circuitry includes at least one transistor. The pair of light-effect transistor access devices are arranged for connecting the bitcell to the first electrical bitline and the second electrical bitline. The optical waveguide wordline is arranged for routing an optical signal to the pair of light-effect transistor access devices.

Example memory devices and example methods for using memory devices are described. An example memory device may include a first electrical bitline, a second electrical bitline, a bitcell, and an optical waveguide wordline. The bitcell is configured to store a bit value and includes storage circuitry and a pair of light-effect transistor access devices. The storage circuitry includes at least one transistor. The pair of light-effect transistor access devices are arranged for connecting the bitcell to the first electrical bitline and the second electrical bitline. The optical waveguide wordline is arranged for routing an optical signal to the pair of light-effect transistor access devices.

In accordance with a first aspect of the present disclosure, a storage device is provided, comprising: a capacitor configured to be charged; a charge circuit configured to charge said capacitor; a pass device coupled between the charge circuit and the capacitor; a control circuit configured to control said pass device; a photosensitive diode coupled between the control circuit and the pass device, such that an input voltage provided by the control circuit to the pass device is reduced if the storage device is exposed to light. In accordance with a second aspect of the present disclosure, a corresponding method of producing a storage device is conceived.

An optical synapse comprises a memristive device for non-volatile storage of a synaptic weight dependent on resistance of the device, and an optical modulator for volatile modulation of optical transmission in a waveguide. The memristive device and optical modulator are connected in control circuitry which is operable, in a write mode, to supply a programming signal to the memristive device to program the synaptic weight and, in a read mode, to supply an electrical signal, dependent on the synaptic weight, to the optical modulator whereby the optical transmission is controlled in a volatile manner in dependence on programmed synaptic weight.

An optical synapse comprises a memristive device for non-volatile storage of a synaptic weight dependent on resistance of the device, and an optical modulator for volatile modulation of optical transmission in a waveguide. The memristive device and optical modulator are connected in control circuitry which is operable, in a write mode, to supply a programming signal to the memristive device to program the synaptic weight and, in a read mode, to supply an electrical signal, dependent on the synaptic weight, to the optical modulator whereby the optical transmission is controlled in a volatile manner in dependence on programmed synaptic weight.

A computer memory system includes an electro-optical chip, an electrical fanout chip electrically connected to an electrical interface of the electro-optical chip, and at least one dual in-line memory module (DIMM) slot electrically connected to the electrical fanout chip. A photonic interface of the electro-optical chip is optically connected to an optical link. The electro-optical chip includes at least one optical macro that converts outgoing electrical data signals into outgoing optical data signals for transmission through the optical link. The optical macro also converts incoming optical data signals from the optical link into incoming electrical data signals and transmits the incoming electrical data signals to the electrical fanout chip. The electrical fanout chip directs bi-directional electrical data communication between the electro-optical chip and a dynamic random access memory (DRAM) DIMM corresponding to the at least one DIMM slot.

A computer memory system includes an electro-optical chip, an electrical fanout chip electrically connected to an electrical interface of the electro-optical chip, and at least one dual in-line memory module (DIMM) slot electrically connected to the electrical fanout chip. A photonic interface of the electro-optical chip is optically connected to an optical link. The electro-optical chip includes at least one optical macro that converts outgoing electrical data signals into outgoing optical data signals for transmission through the optical link. The optical macro also converts incoming optical data signals from the optical link into incoming electrical data signals and transmits the incoming electrical data signals to the electrical fanout chip. The electrical fanout chip directs bi-directional electrical data communication between the electro-optical chip and a dynamic random access memory (DRAM) DIMM corresponding to the at least one DIMM slot.