Techniques for coupling planar qubits to non-planar resonators and related systems and methods
According to some aspects, a quantum mechanical system is provided, comprising a resonator having a plurality of superconducting surfaces and configured to support at least one electromagnetic oscillation mode within a three-dimensional region, wherein the plurality of superconducting surfaces include a first superconducting surface that defines a first plane, and a physical qubit comprising at least one planar component that is planar within the first plane and borders the three-dimensional region.
1. A quantum circuit, comprising:
a resonator having a plurality of superconducting surfaces and configured to support at least one electromagnetic oscillation mode within a three-dimensional region defined by walls on which are disposed the plurality of superconducting surfaces; and
a physical qubit disposed in an opening in one of the walls.
2. The system of claim 1 , wherein the physical qubit comprises at least one planar component that includes at least one Josephson element.
3. The system of claim 2 , wherein the at least one planar component includes a superconducting patch antenna.
4. The system of claim 3 , wherein the superconducting patch antenna comprises a patch with a circular shape.
5. The system of claim 3 , wherein the superconducting patch antenna comprises a patch with a rectangular shape.
6. The system of claim 3 , wherein a superconducting patch of the superconducting patch antenna is connected to the first superconducting surface via at least one Josephson element.
7. The system of claim 1 , wherein the resonator is a three dimensional cavity resonator.
8. The system of claim 1 , wherein the resonator is a whispering gallery mode resonator.
9. The system of claim 8 , wherein the whispering gallery mode resonator includes the first superconducting surface and a second superconducting surface parallel to the first superconducting surface, and wherein the first superconducting surface is separated from the second superconducting surface by a first distance.
10. The system of claim 9 , wherein the whispering gallery mode resonator supports at least two electromagnetic oscillation modes.
11. The system of claim 10 , wherein the at least two electromagnetic oscillation modes are differential modes.
12. The system of claim 10 , wherein a first electromagnetic oscillation mode of the at least two electromagnetic oscillation modes is a parallel mode.
13. The system of claim 12 , wherein a second electromagnetic oscillation mode of the at least two electromagnetic oscillation modes is a perpendicular mode.
14. The system of claim 9 , wherein the first superconducting surface is a first ring-like structure and the second superconducting surface is a second ring-like structure.
15. The system of claim 14 , wherein the first ring-like structure is circularly asymmetric such that a first width of the first ring-like structure in a first plane at a first location is less than a second width of the first ring-like structure in the first plane at a second location, different from the first location.
16. The system of claim 1 , wherein the quantum mechanical system comprises a plurality of resonators.
17. The system of claim 16 , wherein a first resonator of the plurality of resonators is a readout cavity.
18. The system of claim 17 , wherein a second resonator of the plurality of resonators is a storage cavity.
19. The system of claim 1 , wherein:
the plurality of superconducting surfaces include a first superconducting surface that defines a first plane;
the opening is in a first wall on which the first superconducting surface is disposed; and
the physical qubit comprises at least one planar component that is within the first plane.