Photonic spin register, information writing method, and information read-out method

A photonic spin register, comprising:

• a photodetector configured to receive an optical signal that is a pulse amplitude-modulated and serial input signal and convert the optical signal into a photocurrent;
• a plurality of shift register units each including a magnetic material layer having a shape extending in one direction, the plurality of shift register units being arranged in parallel in a direction perpendicular to the one direction;
• a write unit configured to be electrically connected to the photodetector and disposed on and intersecting the plurality of shift register units, wherein when the photocurrent flows through the write unit from the photodetector, the write unit is configured to write spin information into a magnetic domain in the magnetic material layer of each of the plurality of shift register units by transferring information included in the optical signal to a spin state of the magnetic domain in the magnetic material layer due to a spin Hall effect;
• and
• a control unit configured to be electrically connected to the plurality of shift register units and select one shift register unit through which a shift current is allowed to flow from among the plurality of shift register units, wherein
• when the shift current flows in the one direction through the one shift register unit selected by the control unit, a domain wall is configured to move in the magnetic material layer of the one shift register unit, thereby allowing the spin information to move and be buffered in the magnetic material layer.

A photonic spin register, comprising:

• a shift register unit including a magnetic material layer having a shape extending in one direction;
• a plurality of spin Hall materials arranged in the one direction on the magnetic material layer and configured to exhibit spin Hall effects, wherein when a plurality of pulsed currents based on pieces of input information flow in parallel through the plurality of spin Hall materials, respectively, spin-orbit torques are induced to allow a plurality of pieces of spin information to be written into the magnetic material layer;
• a read element disposed on the magnetic material layer so as to be adjacent to the plurality of spin Hall materials;
• and
• an optical modulator configured to be electrically connected to the read element, wherein
• when a shift current flows through the shift register unit in the one direction, domain walls are configured to move in the magnetic material layer, thereby allowing the plurality of pieces of spin information to move and be read out in series as an electrical signal via the read element by a magnetoresistance effect, and
• the optical modulator is configured to convert the electrical signal read out via the read element into an optical signal and output the optical signal.

A method of reading out information, comprising:

• writing spin information into a magnetic domain in a magnetic material layer having a shape extending in one direction by transferring information included in an optical signal that is a pulse amplitude-modulated and serial input signal, to a spin state of the magnetic domain in the magnetic material layer by means of a photocurrent corresponding to the optical signal or by irradiation with the optical signal;
• moving the spin information written into the magnetic domain by moving a domain wall in the magnetic material layer by means of a shift current in the one direction;
• writing and moving the spin information multiple times to sequentially buffer a plurality of pieces of spin information in the magnetic material layer;
• and
• reading out the plurality of pieces of spin information in parallel as a plurality of electrical signals via a plurality of read elements, respectively, by a magnetoresistance effect, the plurality of read elements being arranged in the one direction on the magnetic material layer.

A method of reading out information, comprising:

• causing a plurality of pulsed currents based on pieces of input information to flow in parallel through a plurality of spin Hall materials, respectively, the plurality of spin Hall materials being arranged in one direction on a magnetic material layer having a shape extending in the one direction and configured to exhibit spin Hall effects, the plurality of pulsed currents inducing spin-orbit torques to allow a plurality of pieces of spin information to be written into the magnetic material layer in parallel;
• moving the plurality of pieces of spin information by moving domain walls in the magnetic material layer by means of a shift current in the one direction;
• reading out the plurality of pieces of spin information moving in the magnetic material layer, in series as an electrical signal by a magnetoresistance effect via a read element disposed on the magnetic material layer;
• and
• using an optical modulator to convert the electrical signal into an optical signal and output the optical signal.