Abstract: An optical device includes a magnetic element and a light application part, wherein the light application part configured to apply light to the magnetic element, the magnetic element includes a first ferromagnetic layer to which the light is applied, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and magnetization of the first ferromagnetic layer is inclined with respect to both an in-plane direction in which the first ferromagnetic layer extends and a surface-perpendicular direction perpendicular to a surface on which the first ferromagnetic layer extends in a state in which the light is not applied from the light application part to the magnetic element.

Abstract: A receiving device includes a magnetic element having a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the first ferromagnetic layer is configured to be irradiated with light containing an optical signal with a change of intensity of the light, and wherein the receiving device is configured to receive the optical signal on a basis of an output voltage from the magnetic element.

Abstract: This optical device includes a light-emitting unit that is configured to emit a light; a first magnetic element; and a circuit, wherein the first magnetic element includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, a reflected light reflected by an object to be irradiated with the light is applied to the first magnetic element, a first signal corresponding to an emission of the light from the light-emitting unit is input to the circuit, and a second signal corresponding to an application of the reflected light to the first magnetic element is input from the first magnetic element to the circuit.

Abstract: This light detection element includes a meta-lens that includes nanostructures which are two-dimensionally arranged; and a magnetic element that includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer. Light which passes through the meta-lens is applied to the magnetic element.

Abstract: The light detection element includes a light-sensitive layer configured to generate a voltage when light is applied, a first electrode, and a second electrode. The light-sensitive layer is located between the first electrode and the second electrode. The second electrode is a metal containing at least one element selected from the group consisting of ruthenium, molybdenum, and tungsten.

Abstract: The optical device includes a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and a laser diode. At least a part of light emitted from the laser diode is applied to the magnetic element.

Abstract: A light detection element includes: a plurality of magnetic elements, wherein each of the magnetic elements includes a first ferromagnetic layer that is irradiated with light and a second ferromagnetic layer and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and wherein at least two of the magnetic elements are arranged to be inside a spot of the light applied to the first ferromagnetic layers of the at least two of the magnetic elements.

Abstract: This optical device includes at least one magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, a laser diode, and a waveguide, in which the waveguide includes at least one input waveguide optically connected to the laser diode and an output waveguide connected to the input waveguide, and at least some of light propagating in at least one of the input waveguide and the output waveguide is applied to the magnetic element.

Abstract: An optical device that includes at least one magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a substrate; and a waveguide is provided, wherein the waveguide and the magnetic element are located on or above the substrate, and wherein at least some of light propagating in the waveguide is applied to the magnetic element.

Abstract: A photodetection element includes a magnetic element including a first ferromagnetic layer to which light is applied, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a first electrode in contact with a first surface of the magnetic element, the first surface being located on a first ferromagnetic layer side of the magnetic element in a lamination direction; a second electrode in contact with a second surface of the magnetic element, the second surface being opposite to the first surface; and a first high thermal conductivity layer disposed outside of the first ferromagnetic layer and having higher thermal conductivity than the first electrode.

Abstract: An optical sensor includes a wavelength filter configured to transmit light in a specific wavelength range and a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer. The light passing through the wavelength filter is applied to the magnetic element and the light applied to the magnetic element is detected.

Abstract: A receiving device includes a magnetic element having a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the first ferromagnetic layer is configured to be irradiated with light containing an optical signal with a change of intensity of the light, and wherein the receiving device is configured to receive the optical signal on a basis of an output voltage from the magnetic element.

Abstract: An electrode structure includes: a metal film with an opening formed in a part of the metal film; and a transparent conductive film disposed in the opening, wherein the transparent conductive film is electronically connected to an element and overlaps with the element as viewed in a plan view in a thickness direction of the transparent conductive film.

Abstract: A transceiver device includes: a receiving device including a magnetic element having a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the receiving device is configured to receive an optical signal; a transmission device including a modulated light output element, wherein the transmission device is configured to transmit an optical signal; and a circuit chip including an integrated circuit electrically connected to the magnetic element and the modulated light output element.

Abstract: A photodetection element includes: a first ferromagnetic layer configured to be irradiated with light; a second ferromagnetic layer; and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the first ferromagnetic layer includes a first region in contact with the spacer layer and a second region disposed in a position farther from the space layer than the first region, the first region is made of CoFeB alloy, and the second region is a magnetic material containing Fe and Gd as major constituent elements.

Abstract: A positional information sharing system, a positional information sharing method, and a positional information sharing program that is capable of sharing further accurate positions of respective users between each other.

Abstract: An estimation method includes a heating step in which a recording bit, on which a reference signal is recorded, is heated under each of heating conditions having different heating temperatures, the recording bit being at least one recording bit in the magnetic recording medium, and a measurement step in which a signal intensity with respect to the reference signal recorded in the recording bit after heating is measured under each of the heating conditions of the heating step. Based on the signal intensities with respect to the reference signal respectively measured in the measurement step, the distribution width of the Curie temperatures of the plurality of magnetic grains that form the magnetic recording layer is estimated.

Abstract: In exemplary embodiments, first and second parameters are obtained for each of different temperatures of the magnetic recording layer. The absolute value of the first parameter for each magnetic grain has a minimum value when the temperature of each magnetic grain reaches a predetermined temperature that increases as the Curie temperature increases, and decreases as the Curie temperature decreases. The second parameter is related to the standard deviation of the coercivity distribution of the magnetic grains divided by the coercivity of the magnetic recording layer. The method calculates a value where the absolute measurement value of the first parameter has a minimum value and the temperature of the magnetic recording layer at which the standard deviation of the coercivity distribution of the magnetic grains divided by the coercivity of the magnetic recording layer has a maximum value.

Abstract: An estimation method includes a heating step in which a recording bit, on which a reference signal is recorded, is heated under each of heating conditions having different heating temperatures, the recording bit being at least one recording bit in the magnetic recording medium, and a measurement step in which a signal intensity with respect to the reference signal recorded in the recording bit after heating is measured under each of the heating conditions of the heating step. Based on the signal intensities with respect to the reference signal respectively measured in the measurement step, the distribution width of the Curie temperatures of the plurality of magnetic grains that form the magnetic recording layer is estimated.

Abstract: A measurement method of a magnetic field gradient of a recording magnetic field generated by a magnetic head in a recording medium includes a step of locally heating the recording medium in a nonmagnetic field state where a magnetic field is not applied to the recording medium at all and measuring a temperature gradient of the recording medium in the nonmagnetic field state, a step of locally heating the recording medium in a recording magnetic field application state where the recording magnetic field is applied to the recording medium and measuring a temperature gradient of the recording medium in the recording magnetic field application state, and a step of calculating a magnetic field gradient of the recording magnetic field based on the temperature gradient of the recording medium in the nonmagnetic field state and the temperature gradient of the recording medium in the recording magnetic field application state.