Systems and methods for employing macroscopic resonant tunneling operations in quantum processors are described. New modes of use for quantum processor architectures employ probe qubits to determine energy eigenvalues of a problem Hamiltonian through macroscopic resonant tunneling operations. A dedicated probe qubit design that may be added to quantum processor architectures is also described. The dedicated probe qubit enables improved performance of macroscopic resonant tunneling operations and, consequently, improved performance of the new modes of use described.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A method comprising: programming a quantum processor including a plurality of superconducting flux qubits with a problem Hamiltonian, wherein the problem Hamiltonian has at least one energy eigenvalue; initializing a probe qubit from the plurality of superconducting flux qubits; and scanning a transition rate of the probe qubit for a range of energy bias values of the probe qubit, wherein the transition rate of the probe qubit at least partially depends on a difference between an energy bias value of the probe qubit and an energy eigenvalue of the problem Hamiltonian such that the at least one energy eigenvalue of the problem Hamiltonian approximately corresponds to an energy bias value of the probe qubit to produce a locally maximal transition rate of the probe qubit. 2. The method of claim 1 wherein programming the quantum processor comprises: initializing a set of computation qubits from the plurality of superconducting flux qubits in the quantum processor with a respective energy bias for each qubit in the set of computation qubits and a respective tunneling energy for each qubit in the set of computation qubits; and initializing communicative couplings between the computation qubits in the quantum processor with a respective coupling strength for each coupling device in the set of coupling devices. 3. The method of claim 2 wherein initializing a probe qubit from the plurality of superconducting flux qubits comprises: programming a tunneling energy of the probe qubit, wherein the tunneling energy of the probe qubit is less than the respective tunneling energies of the computation qubits; and communicatively coupling the probe qubit to at least one computation qubit. 4. The method of claim 3 wherein the probe qubit is a superconducting flux qubit from the plurality of superconducting flux qubits that is not included in the set of computation qubits. 5. The method of claim 3, further comprising: programming the at least one computation qubit to which the probe qubit is communicatively coupled with a compensation signal to compensate for the communicative coupling between the probe qubit and the at least one computation qubit. 6. The method of claim 5 wherein communicative coupling between the probe qubit and the at least one computation qubit is characterized by a coupling strength J, the method further comprising: adding a compensation signal to the at least one computation qubit to which the probe qubit is communicatively coupled, wherein the compensation signal has a magnitude of at least approximately 2 J and is of opposite sign to the coupling strength. 7. The method of claim 1 wherein scanning a transition rate of the probe qubit for a range of energy bias values of the probe qubit comprises, for a plurality of energy bias values for the probe qubit ranging from a first value to a second value, iteratively: programming an energy bias of the probe qubit; annealing the probe qubit; and measuring the transition rate of the probe qubit. 8. The method of claim 7 wherein annealing the probe qubit includes lowering the tunneling energy of the probe qubit. 9.-19. (canceled) 20. A quantum processor comprising a superconducting qubit, the superconducting qubit comprising: a loop of superconducting material having a geometric inductance LGp; and a compound Josephson junction that interrupts the loop of superconducting material, wherein the compound Josephson junction includes at least two Josephson junctions that are superconductingly electrically coupled in parallel with one another with respect to the loop of superconducting material; wherein the superconducting qubit has a Josephson inductance LJp greater than the geometric inductance LGp. 21. The quantum processor of claim 20 wherein the superconducting qubit further comprising: a number N of Josephson junctions that interrupt the loop of superconducting material, the N Josephson junctions being superconductingly electrically coupled in series with the compound Josephson junction and superconductingly electrically coupled in series with one another with respect to the loop of superconducting material, and wherein the N Josephson junctions positively contribute to the Josephson inductance LJp. 22. The quantum processor of claim 21 wherein N≧2. 23. The quantum processor of claim 21 further comprising: a plurality of superconducting flux qubits, wherein the plurality of superconducting flux qubits define a Hamiltonian; an inductive coupling device to couple the loop of superconducting material to at least one flux qubit from the plurality of superconducting flux qubits with coupling strength J; and a local bias system for applying a local bias with magnitude of about 2 J and sign opposite to the coupling strength, to the at least one flux qubit from the plurality of superconducting flux qubits. 24. The quantum processor of claim 23 wherein the loop of superconducting material has a persistent current, the value of the persistent current is less than the respective persistent currents of the at least one flux qubit from the plurality of superconducting flux qubits. 25. The quantum processor of claim 24 further comprising: a programming interface in a programming subsystem to apply a magnetic field to the compound Josephson junction that interrupts the loop of superconducting material, wherein varying the magnetic field adjusts the persistent current in the loop of superconducting material. 26. A quantum processor comprising: a plurality of computation qubits, wherein each computation qubit is a superconducting flux qubit that comprises, respectively: a loop of superconducting material having a length of at least X1 and a geometric inductance of at least LGc; and a compound Josephson junction that interrupts the loop of superconducting material, wherein the computation qubit has a Josephson inductance of at most LJc, and the Josephson inductance LJc is less the geometric inductance LGc, at least one coupling device that provides tunable communicative coupling between a set of the computation qubits, wherein the at least one coupling device includes a loop of superconducting material interrupted by at least one Josephson junction; and one or more probe qubits wherein each probe qubit is a superconducting flux qubit comprising, respectively: a loop of superconducting material having a length less than X1 and a geometric inductance LGp; and a compound Josephson junction that interrupts the loop of superconducting material of the probe qubit, wherein the compound Josephson junction includes at least two Josephson junctions that are superconductingly electrically coupled in parallel with one another with respect to the loop of superconducting material of the probe qubit; and wherein a Josephson inductance LJp of the probe qubit is greater than the geometric inductance LGp, wherein at least one of the probe qubits is communicatively coupleable to at least one of the computation qubits. 27.-28. (canceled) 29. The quantum processor of claim 26 wherein at least one of the probe qubits further includes a number N of Josephson junctions that interrupt the loop of superconducting material of the probe qubit, the N Josephson junctions being superconductingly electrically coupled in series with the compound Josephson junction of the probe qubit and superconductingly electrically coupled in series with one another with respect to the loop of superconducting material of the probe qubit, and wherein the N Josephson junctions positively contribute to the Josephson inductance LJp of the probe qubit. 30. (canceled) 31. The quantum processor of claim 26 wherein each computation qubit has a total inductance LTc equal to a sum of the geometric inductance LGc and the Josephson inductance LJc, each probe qubit has a total inductance LTp equal to a sum of the geometric inductance LGp and the Josephson inductance LJp, and the total inductance of each probe qubit LTp is at least approximately equal to the total inductance of each computation qubit LTc. 32. The quantum processor of claim 26 wherein probe qubit is directly communicatively coupleable to at least one of the computation qubits via at least one of galvanic coupling or inductive coupling. 33. The quantum processor of claim 26, further comprising: a coupling device that provides tunable communicative coupling between at least one of the probe qubits and at least one of the computation qubits, wherein the coupling device includes a loop of superconducting material interrupted by at least one Josephson junction, and wherein the at least one probe qubit is communicatively coupleable to at least one of the computation qubits via the coupling device. 34. The quantum processor of claim 26 wherein at least one of the probe qubits further comprises a first persistent current and each of the at least one computation qubits communicatively coupleable to the at least one of the probe qubits further comprises a second persistent current and wherein the first persistent current is lower than the second persistent current.