Superconducting field-programmable gate array
The various embodiments described herein include methods, devices, and systems for operating superconducting circuitry. In one aspect, a programmable circuit includes: (1) a superconducting component arranged in a multi-dimensional array of alternating narrow and wide portions; (2) a plurality of heat sources, each heat source thermally-coupled to, and electrically-isolated from, a respective narrow portion of the multi-dimensional array; and (3) a plurality of electrical terminals, each electrical terminal coupled to a respective wide portion of the multi-dimensional array.
1. A programmable circuit, comprising:
a superconducting component arranged in a multi-dimensional array of alternating narrow and wide portions;
a plurality of heat sources, each heat source thermally-coupled to, and electrically-isolated from, a respective narrow portion of the multi-dimensional array; and
a plurality of electrical terminals, each electrical terminal coupled to a respective wide portion of the multi-dimensional array.
2. The programmable circuit of claim 1 , wherein the plurality of heat sources is configured to selectively provide heat to the respective narrow portions sufficient to transition the respective narrow portions from a superconducting state to a non-superconducting state.
3. The programmable circuit of claim 1 , wherein a first subset of the plurality of heat sources are configured to provide a constant heat to the respective narrow portions sufficient to maintain the respective narrow portions in a non-superconducting state.
4. The programmable circuit of claim 3 , wherein a second subset of the plurality of heat sources are configured as logical inputs to the superconducting component.
5. The programmable circuit of claim 1 , wherein the superconducting component is configured to:
operate in a first logical mode while a third subset of the plurality of heat sources is providing constant heat; and
operate in a second logical mode while a fourth subset of the plurality of heat sources is providing constant heat.
6. The programmable circuit of claim 1 , wherein the superconducting component is arranged in a two-dimensional array.
7. The programmable circuit of claim 1 , wherein the superconducting component is patterned from a single thin film of superconducting material.
8. The programmable circuit of claim 1 , wherein each narrow portion of the multi-dimensional array has substantially the same shape.
9. The programmable circuit of claim 1 , further comprising a current source coupled to the superconducting component, the current source configured to, in the absence of heat from the plurality of heat sources, maintain the superconducting component in a superconducting state.
10. The programmable circuit of claim 1 , further comprising an output circuit coupled to at least a subset of the plurality of electrical terminals.
11. The programmable circuit of claim 1 , wherein one or more of the plurality of electrical terminals are coupled to a reference node.
12. A method of operating a programmable circuit, comprising:
providing a first current to a superconducting component arranged in a multi-dimensional array of alternating narrow and wide portions, the first current configured to maintain the superconducting component in a superconducting state;
configuring the superconducting component to perform a first logical operation by providing constant heat to a first subset of the narrow portions, the constant heat configured to transition the first subset of the narrow portions from the superconducting state to a non-superconducting state;
while the superconducting component is configured to perform the first logical operation:
receiving one or more inputs via a second subset of the narrow portions, distinct from the first subset; and
obtaining an electrical output via a subset of the wide portions, the electrical output corresponding to a result of the first logical operation on the one or more inputs.
13. The method of claim 12 , further comprising:
configuring the superconducting component to perform a second logical operation, distinct from the first logical operation, by providing constant heat to a third subset of the narrow portions, the constant heat configured to transition the third subset of the narrow portions from the superconducting state to the non-superconducting state;
while the superconducting component is configured to perform the second logical operation:
receiving one or more second inputs via a fourth subset of the narrow portions, distinct from the third subset; and
obtaining a second electrical output via a second subset of the wide portions, the second electrical output corresponding to a result of the second logical operation on the one or more second inputs.
14. The method of claim 12 , wherein the first logical operation is selected from a group consisting of:
a logical AND operation;
a logical OR operation;
a majority gate operation; and
an input counting operation.
15. The method of claim 12 , wherein the one or more inputs comprise heat inputs configured to transition the second subset of the narrow portions from the superconducting state to the non-superconducting state.
16. The method of claim 12 , wherein configuring the superconducting component to perform the first logical operation comprises coupling one or more of the wide portions to a reference node.