Four-input josephson gates
AssigneeNorthrop Grumman Systems Corporation
InventorsJack R. Powell, III, Alexander L. Braun
Life of this patent
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Abstract
Superconducting methods of determining AND, OR, AND-OR, and OR-AND logic values use single flux quantum (SFQ) pulses to assert logical inputs of a reciprocal quantum logic (RQL) gate by placing currents in input storage loops in the RQL gate and, based on the currents in the storage loops, triggering logical decision Josephson junctions (JJs) in the gate, such that an assertion or de-assertion signal corresponding to the logical function of the gate is observed at the output. The methods permit for outputs based on at least four logical inputs to be achieved.
Claims20
A method of determining a logic value comprising:
- providing single flux quantum (SFQ) pulses to assert all logical inputs of a reciprocal quantum logic (RQL) AND gate having at least four logical inputs;
- placing currents in all input storage loops in the RQL gate;
- triggering a first and a second of three logical decision Josephson junctions (JJs) in the RQL gate, thereby triggering a third logical decision JJ of the three logical decision JJs in the RQL gate;
- and
- propagating an assertion signal from an output of the RQL AND gate.
A method of determining a logic value comprising:
- providing single flux quantum (SFQ) pulses to assert any logical input of a reciprocal quantum logic (RQL) OR gate having at least four logical inputs;
- placing currents in one or more input storage loops in the RQL gate;
- triggering either or both of a first or a second of three logical decision Josephson junctions (JJs) in the RQL gate, thereby triggering a third logical decision JJ of the three logical decision JJs in the RQL gate;
- and
- propagating an assertion signal from an output of the RQL OR gate.
A method of determining a logic value comprising:
- providing single flux quantum (SFQ) pulses to assert at least two paired logical inputs of a reciprocal quantum logic (RQL) AO22 gate having at least four logical inputs;
- placing currents in at least two input storage loops in the RQL gate, the at least two input storage loops associated with the at least two paired logical inputs;
- triggering at least a first of three logical decision Josephson junctions (JJs) in the RQL gate, thereby triggering a third logical decision JJ of the three logical decision JJs in the RQL gate;
- and
- propagating an assertion signal from an output of the RQL AO22 gate.
A method of determining a logic value comprising:
- providing single flux quantum (SFQ) pulses to assert at least two unpaired logical inputs of a reciprocal quantum logic (RQL) OA22 gate having at least four logical inputs;
- placing currents in at least two input storage loops in the RQL gate, the at least two input storage loops associated with the at least two unpaired logical inputs;
- triggering a first and a second of three logical decision Josephson junctions (JJs) in the RQL gate, thereby triggering a third logical decision JJ of the three logical decision JJs in the RQL gate;
- and
- propagating an assertion signal from an output of the RQL OA22 gate.
Dependencies are inferred from the claim text.