Incorporating arrays of Josephson junctions in a Josephson junction ring modulator in a Josephson parametric converter

1. A Josephson parametric converter, comprising:

a multi-Josephson junction ring modulator having arrays of N Josephson junctions arranged m a ring configuration with nodes inter-dispersed between the arrays, wherein N is an integer having a value greater than one; and

a first and a second resonator formed from lumped-element capacitors that shunt the multi-Josephson junction ring modulator and respectively enable a first and a second mode of the Josephson parametric converter.

2. The Josephson parametric converter of claim 1 , wherein the N Josephson junctions in each of the arrays are connected in series.

3. The Josephson parametric converter of claim 1 , wherein the first resonator comprises at least one capacitor shunted across a first node and a third node from among the nodes, and the second resonator comprises at least one other capacitor shunted across a second node and a fourth node from among the nodes.

4. The Josephson parametric converter of claim 3 , wherein multi-Josephson junction ring modulator has two opposing pairs of nodes, a first of the two opposing pairs of nodes formed from the first node and the third node, and a second of the two opposing pairs of nodes formed from the second node and the fourth node.

5. The Josephson parametric converter of claim 1 , further comprising a first, a second, a third, and a fourth coupling capacitor, each having a first electrode connected to a respective different one of the nodes of the multi-Josephson junction ring modulator, and having a second electrode for connecting to a respective one of a plurality of feedlines.

6. The Josephson parametric converter of claim 1 , wherein the Josephson parametric convener is formed such that a total inductance of the Josephson parametric converter is dominated by an inductance contribution of the multi-Josephson junction ring modulator to provide a dynamical bandwidth of at least 100 MHz for the Josephson parametric converter at 20 dB of gain.

7. The Josephson parametric converter of claim 1 , wherein the first and the second resonator are further formed from lumped-element inductance, and wherein the arrays of Josephson junctions in the Josephson junction ring modulator in conjunction with using a lumped-element implementation for the resonators enables a maximum input power of at least −120 dBm at 20 dB of gain for the Josephson parametric converter, wherein the lumped-element implementation for the resonators comprises the lumped-element capacitors and the lumped-element inductance.

8. The Josephson parametric converter of claim 1 , wherein a number of the nodes in the ring arrangement is four.

9. The Josephson parametric converter of claim 1 , wherein the Josephson parametric convener is configured to perform wave mixing of three microwave signals for quantum information processing.

10. The Josephson parametric converter of claim 9 , wherein the Josephson parametric converter is configured to selectively perform unitary frequency conversion or quantum-limited amplification in a microwave domain based on a pump tone frequency.

11. A method, comprising:

forming a Josephson parametric converter, wherein said forming step includes;

forming a multi-Josephson junction ring modulator having arrays of N Josephson junctions arranged in a ring configuration with nodes inter-dispersed between the arrays, wherein N is an integer having a value greater than one; and

forming a first and a second resonator from lumped-element capacitors that shunt the multi-Josephson junction ring modulator and respectively enable a first and a second mode of the Josephson parametric converter.

12. The method of claim 11 , wherein the N Josephson junctions in each of the arrays are connected in series.

13. The method of claim 11 , wherein forming the first and the second resonator comprise:

shunting at least one capacitor across a first node and a third node from among the nodes; and

shunting at least one other capacitor across a second arcade and a fourth node from among the nodes.

14. The method of claim 13 , wherein multi-Josephson junction ring modulator is formed to have two opposing pairs of nodes, a first of the two opposing pairs of nodes formed from the first node and the third node, and a second of the two opposing pairs of nodes formed from the second node and the fourth node.

15. The method of claim 11 , further comprising forming a first, a second, a third, and a fourth coupling capacitor, each having a first electrode connected to a respective different one of the nodes of the multi-Josephson junction ring modulator, and liming a second electrode for connecting to a respective one of a plurality of feedlines.

16. The method of claim 11 , wherein the Josephson parametric convener is formed such that a total inductance of the Josephson parametric converter is dominated by an inductance contribution of the multi-Josephson junction ring modulator to provide a dynamical bandwidth of at least 100 MHz for the Josephson parametric converter.

17. The method of claim 11 wherein the first and the second resonator are further formed from lumped-element inductance, and wherein the arrays of Josephson junctions in the Josephson junction ring modulator in conjunction with using a lumped-element implementation for the resonators enables a maximum input power of at least −120 dBm at 20 dB of gain for the Josephson parametric converter, wherein the lumped-element implementation for the resonators comprises the lumped-element capacitors and the lumped-element inductance.

18. The method of claim 11 , wherein a number of the nodes in the ring arrangement is four.

19. The method of claim 11 , wherein the Josephson parametric converter is configured to perform wave mixing of three input waves for quantum information processing.

20. The method of claim 19 , wherein the Josephson parametric converter is configured to selectively perform unitary frequency conversion or quantum-limited amplification in a microwave domain based on a pump tone frequency.