Direct current powered clockless superconducting logic family using dynamic internal states
View Patent ↗Techniques regarding a DSFQ logic family are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a dynamic single flux quantum logic circuit that has a self-resetting internal state and can be powered by direct current. Further, the self-resetting internal state can be characterized by two time constants.
1. An apparatus, comprising:
a first circuit branch comprising a first Josephson junction arranged in series with a resistor;
a second circuit branch connected in parallel with the first circuit branch and comprising a second Josephson junction, wherein the first circuit branch is a dynamic circuit branch and wherein the second circuit branch is a static circuit branch;
a superconducting inductor connected in series with a parallel connection of the first circuit branch and the second circuit branch; and
an output port electrically biased by an energy-efficient rapid single flux quantum bias source comprised of a limiter Josephson Junction connected in series with a second inductor.
2. The apparatus of claim 1 , wherein the superconducting inductor connected in series with the parallel connection of the first circuit branch and the second circuit branch establishes a dynamic self-resetting internal state characterized by a first time constant and a second time constant.
3. The apparatus of claim 2 , wherein the first time constant is an intrinsic constant to Josephson junctions.
4. The apparatus of claim 2 , wherein the second time constant is defined by the resistor.
5. A method, comprising:
forming a first circuit branch comprising a first Josephson junction arranged in series with a resistor; and
forming a second circuit branch coupled with the first circuit branch and comprising a second Josephson junction, wherein the first circuit branch is a dynamic circuit branch and wherein the second circuit branch is a static circuit branch.
6. The method of claim 5 , further comprising:
connecting a superconducting inductor in series with a parallel connection of the first circuit branch and the second circuit branch.
7. The method of claim 6 , wherein a first critical current of the first Josephson junction is a first value and a second critical current of the second Josephson junction is a second value, and wherein the first value is less than the second value.
8. The method of claim 5 , wherein the superconducting inductor connected in series with the parallel connection of the first circuit branch and the second circuit branch establishes a dynamic self-resetting internal state characterized by a first time constant and a second time constant.
9. The method of claim 8 , wherein the first time constant is an intrinsic time constant to Josephson junctions.
10. The method of claim 8 , wherein the second time constant is defined by the resistor.
11. An apparatus, comprising:
a first circuit branch comprising a first Josephson junction arranged in series with a resistor; and
a second circuit branch coupled with the first circuit branch and comprising a second Josephson junction, wherein the first circuit branch is a dynamic circuit branch and wherein the second circuit branch is a static circuit branch.
12. The apparatus of claim 11 , further comprising a superconducting inductor connected in series with a parallel connection of the first circuit branch and the second circuit branch.
13. The apparatus of claim 12 , wherein the superconducting inductor connected in series with the parallel connection of the first circuit branch and the second circuit branch establishes a dynamic self-resetting internal state.
14. The apparatus of claim 13 , wherein the dynamic self-resetting internal state is characterized by a first time constant and a second time constant.
15. The apparatus of claim 13 , wherein the first time constant is an intrinsic constant to Josephson junctions.
16. The apparatus of claim 13 , wherein the second time constant is defined by the resistor.
17. The apparatus of claim 11 , wherein a first critical current of the first Josephson junction is a first value and a second critical current of the second Josephson junction is a second value, and wherein the first value is less than the second value.
18. The apparatus of claim 11 , wherein a first critical current of the first Josephson junction is a first value and a second critical current of the second Josephson junction is a second value, and wherein the first value is equal to the second value.
19. The apparatus of claim 11 , wherein the resistor is an external shunt resistor adapted to damp the plasma resonance of the first Josephson junction and the second Josephson junction.