A higher degree of interactions between qubits is realizable. This disclosure generally relates to devices, and architectures for quantum instruments comprising quantum devices and techniques for operating the same. Systems and processors for creating and using higher degree interactions between qubits may be found herein. Higher order interactions include interactions among three or more qubits. Methods for creating and using higher degree interactions among three or more qubits on a quantum processor may be found herein.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A quantum device comprising: a first qubit; a second qubit; a third qubit; and a first coupler inductively coupled to each of the first, the second, and the third qubits by a respective mutual inductance, wherein the first coupler is operable to provide a third-order interaction or a higher-order interaction among the first, the second, and the third qubits. 2. The quantum device of claim 1 wherein the first coupler is inductively coupled to each of the first, the second, and the third qubits by a respective mutual inductance, directly, and without an intervening coupler. 3. The quantum device of claim 1 wherein the first coupler is the only coupler that is inductively coupleable to each of the first, the second, and the third qubits. 4. The quantum device of claim 1 wherein the coupler comprises a closed loop of material that superconducts at or below a critical temperature, the closed loop of material interrupted by a compound Josephson junction, and further comprises a first, a second, and a third interface structure spaced along the closed loop of material, a respective one of the inductive interface structures for each of the first, the second, and the third qubits. 5. The quantum device of claim 4 wherein the first, the second, and the third interface structures of the first coupler are positioned and operable to selective inductively couple with respective ones of the first, the second, and the third qubits. 6. The quantum device of claim 5, further comprising: at least a fourth qubit; and wherein the closed loop of material of the first coupler has at least a fourth inductive interface structure positioned and operable to selectively inductively couple with the fourth qubit, and the first coupler is operable to provide a third-order interaction or a higher-order interaction among the first, the second, the third and the fourth qubits. 7. The quantum device of claim 6, wherein the first coupler is the only coupler that is directly inductively coupleable to the first, the second, the third, and the fourth qubits. 8. The quantum device of claim 6, wherein the first coupler is operable to provide a third-order magnetic susceptibility among the first, the second, the third, and the fourth qubits, the quantum device further comprising: a second coupler inductively coupled to each of the first, the second, the third, and the fourth qubits by a respective mutual inductance operable to provide a linear magnetic susceptibility among the first, the second, the third, and the fourth qubits, wherein the first coupler is tunable to at least one of optimize or enhance a strength of a 4-local interaction among the first, the second, the third, and the fourth qubits, and the second coupler is tunable to null, or at least partially compensate, for a strength of a number of 2-local interactions between pairs of the first, the second, the third, and the fourth qubits. 9. The quantum device of claim 8, wherein the second coupler comprises a closed loop of material that superconducts at or below a critical temperature, the closed loop of the second coupler interrupted by a compound Josephson junction, the closed loop of the second coupler having a first inductive interface structure, a second inductive interface structure, a third inductive interface structure, and a fourth inductive interface structure, the first, the second, the third, and the fourth inductive interface structures positioned and operable to selectively inductively couple with respective ones of the first, the second, the third qubit, and the fourth qubits. 10. The quantum device of claim 1, wherein: the first qubit has a state, the state of the first qubit representative of a first input to the quantum device; the second qubit has a state, the state of the second qubit representative of a second input to the quantum device; the third qubit has a state, the state of the third qubit representative of an output from the quantum device; and the first coupler is further operable to provide a second-order interaction between each pair of qubits selected from the first, the second and the third qubits. 11. The quantum device of claim 10, wherein the quantum device is a quantum processor. 12. The quantum device of claim 10, wherein the quantum device is a reversible logic gate. 13. The quantum device of claim 12, wherein the reversible logic gate is a reversible exclusive OR (XOR) logic gate, and wherein: an absolute value of a strength of a third-order interaction among the three qubits is non-zero; an absolute value of a strength of a second-order interaction between each pair of qubits selected from the three qubits is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude; and a number of absolute values of local bias on each of the three qubits is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude. 14. The quantum device of claim 12, wherein the reversible logic gate is a reversible NOT AND (NAND) logic gate, and wherein: an absolute value of a strength of a third-order interaction among the three qubits is non-zero; an absolute difference between the strength of the third-order interaction among the three qubits and a strength of a second-order interaction between the first qubit and the third qubit is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude; an absolute difference between the strength of the third-order interaction among the three qubits and the strength of a second-order interaction between the second qubit and the third qubit is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude; an absolute value of a strength of a second-order interaction between the first qubit and the second qubit is smaller than the absolute value of the third-order interaction among the three qubits by at least one order of magnitude; a respective absolute value of a strength of a local bias on each of the first qubit and the second qubit is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude; and an absolute difference between the strength of the third-order interaction among the three qubits and a strength of a local bias on the third qubit is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude. 15. The quantum device of claim 1, wherein: the first qubit communicatively coupled to receive a first input to the quantum device and operable to represent the first input to the quantum device via a state of the first qubit; the second qubit communicatively coupled to receive a second input to the quantum device and operable to represent the second input to the quantum device via a state of the second qubit; the third qubit communicatively coupled to receive an output from the quantum device and operable to represent the output from the quantum device via a state of the third qubit; the first coupler comprising a closed loop of material that superconducts at or below a critical temperature, the closed loop of the first coupler having a first inductive interface structure, a second inductive interface structure and a third inductive interface structure, the first, the second, and the third inductive interface structures positioned and operable to selectively inductively couple with respective ones of the first, the second and the third qubits, the first coupler further comprising a compound Josephson junction that interrupts the closed loop, the first coupler further operable to provide a second-order interaction between each pair of qubits selected from the first, the second and the third qubits. 16. The quantum device of claim 15, wherein the quantum device is a quantum processor. 17. The quantum device of claim 15, wherein the quantum device is a reversible logic gate. 18. The quantum device of claim 17, wherein the reversible logic gate is a reversible exclusive OR (XOR) logic gate, and wherein an absolute value of a strength of a third-order interaction among the three qubits is non-zero; an absolute value of a strength of a second-order interaction between each pair of qubits selected from the three qubits is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude; and a number of absolute values of local bias on each of the three qubits is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude. 19. The quantum device of claim 17, wherein the reversible logic gate is a reversible NOT AND (NAND) logic gate, and wherein: an absolute value of the strength of the third-order interaction among the three qubits is non-zero; an absolute difference between the strength of the third-order interaction among the three qubits and a strength of a second-order interaction between the first qubit and the third qubit is smaller than the absolute value of the strength the third-order interaction among the three qubits by at least one order of magnitude; an absolute difference between a strength of the third-order interaction among the three qubits and a strength of a second-order interaction between the second qubit and the third qubit is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude; an absolute value of a strength of a second-order interaction between the first qubit and the second qubit is smaller than the absolute value of the third-order interaction among the three qubits by at least one order of magnitude; a respective absolute value of a strength of a local bias on each of the first qubit and the second qubit is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude; and an absolute difference between the strength of the third-order interaction among the three qubits and a strength of a local bias on the third qubit is smaller than the absolute value of the strength of the third-order interaction among the three qubits by at least one order of magnitude. 20. The quantum device of any of claim 1, wherein at least one qubit is a superconducting qubit. 21. The quantum device of claim 20, wherein the superconducting qubit is a superconducting flux qubit. 22. The quantum device of claim 17, wherein the reversible logic gate is a reversible exclusive OR (XOR) logic gate, and wherein: a magnitude of the second-order interactions between each pair of qubits selected from the three qubits is essentially zero, and the magnitude of the third-order interaction among the three qubits is greater than zero. 23. The quantum device of claim 17, wherein the reversible logic gate is a reversible NOT AND (NAND) logic gate, and wherein: a magnitude of the second-order interaction between the first qubit and the third qubit is about the same as the magnitude of the second-order interaction between the second qubit and the third qubit; a magnitude of the second-order interaction between the second qubit and the third qubit is about the same as the magnitude of the third-order interaction among the three qubits; a magnitude of the third-order interaction among the three qubits is about the same as a local bias on the third qubit; the local bias on the third qubit is non-zero; a magnitude of the second-order interaction between the first qubit and the second qubit is about the same as a local bias on the first qubit; the local bias on the first qubit is about the same as a local bias on the second qubit; and the local bias on the second qubit is essentially zero. 24. A quantum device comprising: a number n qubits where the number n is a number greater than 2; and a coupler inductively coupled to each of the number n qubits by a respective mutual inductance, wherein the coupler is tunable to at least one of optimize or enhance at least one of a magnetic susceptibility of order a (n−1) so as to provide an n-local interaction among the qubits, or at least one k-local interaction among one or more subsets of the n qubits, where 1≤k≤n. 25. The quantum device of claim 24, wherein the coupler comprises a closed loop of material that superconducts at or below a critical temperature, the closed loop of the coupler having at least one inductive interface structure, the at least one inductive interface structure positioned and operable to selectively inductively couple with a respective at least one of the n qubits. 26. The quantum device of 24, wherein at least one of the n qubits is a superconducting qubit. 27. The quantum device of claim 25, wherein the superconducting qubit is a superconducting flux qubit.