Implementing computing functions using skyrmions
Systems and methods are provided that exploit local dynamics of a skyrmion to perform a computing function. A magnetic system hosts a skyrmion that transitions among a plurality of states, with each of the plurality of states having an associated switching probability. A bias source provides energy to the magnetic system as to adjust a switching probability associated with one of the plurality of states. A readout component measures a state of the skyrmion.
1. A system comprising:
a magnetic system hosting a skyrmion, the skyrmion transitioning among a plurality of states, each of the plurality of states having an associated switching probability;
a bias source that provides energy to the magnetic system as to adjust a switching probability associated with one of the plurality of states;
a readout component for measuring a state of the skyrmion;
a computing component that generates a random bit from the state of the skyrmion measured at the readout component.
2. The system of claim 1 , wherein the skyrmion is a first skyrmion of a plurality of skyrmions, the bias source is a first bias source, and the magnetic system hosts the first skyrmion and a second skyrmion of the plurality of skyrmions, the system further comprising:
a second bias source that provides energy to the magnetic system as to adjust a switching probability associated with one of a plurality of states of the second skyrmion; and
a coupling control that tunes a dynamic coupling between the first and second skyrmions.
3. The system of claim 2 , wherein each of the first skyrmion and the second skyrmion is implemented on a Hall cross, and the readout component measures a Hall resistance representing a state of a system formed by the two skyrmions.
4. The system of claim 3 , wherein a value for the measured Hall resistance represents one of a logical OR operation and a logical AND operation on an input provided by the first bias source and an input provided by the second bias source.
5. The system of claim 1 , wherein the bias source comprises one of an electromagnetic source, a current source, a heating element, an optic source, a spin wave source, and a voltage source.
6. The system of claim 1 , wherein the magnetic system is implemented as one of a magnetic multilayer, a bulk magnetic material, and a thin film.
7. The system of claim 1 , wherein the magnetic system includes a first pinning site associated with the skyrmion and at least two additional pinning sites, in which each of the plurality of states are represented by one of the at least two additional pinning sites.
8. The system of claim 1 , wherein the plurality of states includes more than two states, and the computing component generates at least two random bits from the state of the skyrmion measured at the readout component.
9. The system of claim 1 , wherein the skyrmion is a first skyrmion of a plurality of skyrmions, the bias source is a first bias source, and the magnetic system hosts the first skyrmion and a second skyrmion of the plurality of skyrmions, the system further comprising a second bias source that provides energy to the magnetic system as to adjust a switching probability associated with one of a plurality of states of the second skyrmion, and the readout component measuring a state of each of the first skyrmion and the second skyrmion, the measured state of each skyrmion being used to generate a random bit.
10. A method comprising:
fabricating a magnetic system having a plurality of pinning sites;
generating a skyrmion at one of the plurality of pinning sites, the skyrmion being generated as to be strongly pinned to the one of the plurality of pinning sites and weakly pinned to at least two other pinning sites of the pinning sites, with the skyrmion transitioning among a set of a plurality of states, each of the plurality of states being associated with one of the at least two other pinning sites and having an associated switching probability;
providing energy to the magnetic system as to adjust a switching probability associated with one of the plurality of states; and
measuring a state of the skyrmion of the plurality of states.
11. The method of claim 10 , wherein fabricating the magnetic system comprises depositing a magnetic multilayer.
12. The method of claim 11 , wherein deposition rate of the deposition process is controlled to manipulate pinning strengths of naturally-existing pinning sites.
13. The method of claim 11 , wherein fabricating the magnetic system having the plurality of pinning sites comprises introducing a hole or embedding impurity atoms into the magnetic multilayer.
14. The method of claim 10 , wherein generating a skyrmion at one of the plurality of pinning sites comprises one of modifying a magnetic field applied to the one of the plurality of pinning sites, applying an electric current to the one of the plurality of pinning sites, applying a thermal pulse to the one of the plurality of pinning sites, applying an optic pulse to the one of the plurality of pinning sites, applying a magnon pulse to the one of the plurality of pinning sites, and applying a voltage pulse to the one of the plurality of pinning sites.
15. The method of claim 10 , wherein generating a skyrmion at one of the plurality of pinning sites comprises generating a plurality of skyrmions and applying energy to the magnetic system to annihilate one of the plurality of skyrmions.
16. The method of claim 10 , wherein providing energy to the magnetic system as to adjust the switching probability associated with one of the plurality of states comprises providing one of an applied magnetic field, a current, thermal energy, optics, a magnon pulse, and voltages to the magnetic system.
17. The method of claim 10 , wherein generating the skyrmion at the one of the plurality of pinning sites comprises generating a plurality of skyrmions, each associated with a set of the plurality of pinning sites, wherein respective positions of at least a first skyrmion of the plurality of skyrmion and a second skyrmion of the plurality of skyrmion in the magnetic system are selected such that the first skyrmion is coupled to the second skyrmion in an anti-correlated manner.
18. The method of claim 17 , further comprising providing energy to the magnetic system to tune the anti-correlated coupling between the first skyrmion and the second skyrmion.
19. The method of claim 10 , wherein generating the skyrmion at the one of the plurality of pinning sites comprises generating the skyrmion at the one of the plurality of pinning sites with a size selected to provide a specific base switching probability for at least one of the plurality of states associated with the skyrmion.
20. A system comprising:
a magnetic system hosting a plurality of skyrmions, each skyrmion transitioning among a plurality of states, each of the plurality of states having an associated switching probability, wherein each skyrmion is coupled to its neighboring skyrmions in their fluctuating dynamics;
a bias source that provides energy to a first subset of the plurality of skyrmions as to adjust a switching probability associated with at least one of the first subset of the plurality of skyrmions; and
a readout component for measuring a state of a second subset of the plurality of skyrmions.
21. The system of claim 20 , wherein the union of the first subset of skyrmions and the second subset of skyrmions is a proper subset of the plurality of skyrmions.