Systems and methods for addressing devices in a superconducting circuit
Superconducting integrated circuits may advantageously employ superconducting resonators coupled to a microwave transmission line to efficiently address superconducting flux storage devices. In an XY-addressing scheme, a global flux bias may be applied to a number of superconducting flux storage devices via a low-frequency address line, and individual superconducting flux storage devices addressed via application of high-frequency pulses via resonators driven by the microwave transmission line. Frequency multiplexing can be employed to provide signals to two or more resonators. A low-frequency current bias may be combined with a high-frequency current in one or more superconducting resonators to provide Z-addressing. A low-frequency current bias may be combined with a high-frequency current in one or more superconducting resonators to eliminate a flux bias line. A low-frequency current bias may be used at room temperature to identify the presence of a DC short, an open, and/or an unexpected resistance in a superconducting resonator.
1. A superconducting integrated circuit comprising:
a microwave transmission line;
a signal source;
one or more electronic filters;
a first superconducting resonator comprising a first superconducting resonator body that is superconductive in a range of temperatures, the first superconducting resonator communicatively coupled to the microwave transmission line; and
a second superconducting resonator comprising a second superconducting resonator body that is superconductive in a range of temperatures, the second superconducting resonator communicatively coupled to the microwave transmission line, the second superconducting resonator body communicatively coupled in series with the first superconducting resonator body; wherein the signal source is operable to provide a DC bias to the first and the second superconducting resonators by a signal path that includes the one or more electronic filters, and
a switch to dynamically isolate a device, the switch comprising:
a plurality of cascade elements superconductingly electrically communicatively coupled in series, each cascade element of the plurality of cascade elements comprising:
a respective first plurality of N Superconducting Quantum Interference Devices (SQUIDs) superconductingly electrically communicatively coupled in series in a first arm, each SQUID of the first plurality of SQUIDs comprising at least one Josephson Junction;
a respective matching capacitor; and
a respective second plurality of M SQUIDs superconductingly electrically communicatively coupled in series in a second arm, opposite the first arm with respect to the matching capacitor, each SQUID of the second plurality of SQUIDs comprising at least one Josephson Junction.
2. The superconducting integrated circuit of claim 1 wherein the microwave transmission line is one of a microstrip transmission line, a stripline transmission line, a coaxial transmission line, and a co-planar waveguide transmission line.
3. The superconducting integrated circuit of claim 1 wherein the signal source is operable to provide at least one of a low-frequency and a DC signal.
4. The superconducting integrated circuit of claim 1 wherein the one or more electronic filters are one of a low-pass filter, a notch filter, and a band-pass filter.
5. The superconducting integrated circuit of claim 1 wherein the first and the second superconducting resonators are members of an array of three or more superconducting resonators.
6. The superconducting integrated circuit of claim 1 wherein the first and the second superconducting resonators are capacitively communicatively coupled to the microwave transmission line.
7. The superconducting integrated circuit of claim 1 wherein the superconducting integrated circuit is operable at a higher temperature than a cryogenic temperature to identify a presence of at least one of an electrical short, an electrical open, and an unexpected resistance in at least one of the first and the second superconducting resonators.
8. The superconducting integrated circuit of claim 1 , further comprising a flux bias line and at least one filtering element along the flux bias line, the filtering element operable to cause the switch to operate at an operating speed, wherein the at least one filtering element is selected from a group consisting of: a passive filtering elements, inductive chokes and kinetic inductors.
9. A superconducting integrated circuit comprising:
a microwave transmission line;
a signal source;
an electronic filter;
a superconducting resonator comprising a superconducting resonator body that is superconductive in a range of temperatures, the superconducting resonator communicatively coupled to the microwave transmission line, the superconducting resonator body communicatively coupled to the signal source by the electronic filter; and
a superconducting device that is communicatively coupled to the superconducting resonator, the superconducting device operable to receive a programming signal that includes at least a DC bias from the signal source by a first signal path that includes the electronic filter.
10. The superconducting integrated circuit of claim 9 wherein the microwave transmission line is one of a microstrip transmission line, a stripline transmission line, a coaxial transmission line, and a co-planar waveguide transmission line.
11. The superconducting integrated circuit of claim 9 wherein the signal source is operable to provide at least one of a low-frequency and a DC signal.
12. The superconducting integrated circuit of claim 9 wherein the electronic filter is one of a low-pass filter, a notch filter, and a band-pass filter.
13. The superconducting integrated circuit of claim 9 wherein the superconducting resonator is a member of an array of two or more superconducting resonators.
14. The superconducting integrated circuit of claim 9 wherein the superconducting resonator is capacitively communicatively coupled to the microwave transmission line.
15. The superconducting integrated circuit of claim 9 wherein the superconducting resonator body is galvanically communicatively coupled to the signal source by the electronic filter.
16. The superconducting integrated circuit of claim 9 wherein the superconducting device is communicatively coupled to the superconducting resonator via at least one of: a galvanic coupling and an inductive coupling.
17. The superconducting integrated circuit of claim 9 wherein the superconducting device is a superconducting flux storage device including a digital-to-analog converter (DAC).
18. The superconducting integrated circuit of claim 9 wherein the programming signal further includes a high-frequency signal by a second signal path that includes the microwave transmission line.
19. The superconducting integrated circuit of claim 9 , further comprising:
a switch to dynamically isolate a device, the switch comprising:
a plurality of cascade elements superconductingly electrically communicatively coupled in series, each cascade element of the plurality of cascade elements comprising:
a respective first plurality of N Superconducting Quantum Interference Devices (SQUIDs) superconductingly electrically communicatively coupled in series in a first arm, each SQUID of the first plurality of SQUIDs comprising at least one Josephson Junction;
a respective matching capacitor;
a respective second plurality of M SQUIDs superconductingly electrically communicatively coupled in series in a second arm, opposite the first arm with respect to the matching capacitor, each SQUID of the second plurality of SQUIDs comprising at least one Josephson Junction; and
a flux bias line and at least one filtering element along the flux bias line, the filtering element operable to cause the switch to operate at an operating speed, wherein the at least one filtering element is selected from a group consisting of: a passive filtering elements, inductive chokes and kinetic inductors.