Abstract: A structure comprising a tank circuit inductively coupled to a flux qubit or a phase qubit. In some embodiments, a low temperature preamplifier is in electrical communication with the tank circuit. The tank circuit comprises an effective capacitance and an effective inductance that are in parallel or in series. In some embodiments, the effective inductance comprises a multiple winding coil of wire. A method that includes the steps of (i) providing a tank circuit and a phase qubit that are inductively coupled, (ii) reading out a state of the phase qubit, (iii) applying a flux to the phase qubit that approaches a net zero flux, (iv) increasing a level of flux applied to the phase qubit, and (v) observing a response of the tank circuit in a readout device.

Abstract: A method for quantum computing using a quantum system comprising a plurality of qubits is provided. The system can be in any one of at least two configurations at any given time including one characterized by an initialization Hamiltonian HO and one characterized by a problem Hamiltonian HP. The problem Hamiltonian HP has a ground state. Each respective first qubit in the qubits is arranged with respect to a respective second qubit in the qubits such that they define a predetermined coupling strength. The predetermined coupling strengths between the qubits in the plurality of qubits collectively define a computational problem to be solved. In the method, the system is initialized to HO and is then adiabatically changed until the system is described by the ground state of the problem Hamiltonian HP. Then the state of the system is read out by probing an observable of the ?X Pauli matrix operator.

Abstract: A computer program product with computer program mechanism embedded therein is provided. The mechanism has instructions for initializing a quantum system, which includes a plurality of qubits, to an initialization Hamiltonian HO. The system is capable of being in one of at least two configurations at any give time including HO and a problem Hamiltonian HP. Each respective first qubit in the plurality of qubits is arranged with respect to a respective second qubit in the plurality of qubits such that the first respective qubit and the second respective qubit define a predetermined coupling strength. The predetermined coupling strengths between the qubits in the plurality of qubit collectively define a computational problem to be solved. The mechanism further comprises instructions for adiabatically changing the system until it is described by the ground state of the problem Hamiltonian HP and instructions for reading out the state of the system.

Abstract: A structure comprising a tank circuit inductively coupled to a flux qubit or a phase qubit. In some embodiments, a low temperature preamplifier is in electrical communication with the tank circuit. The tank circuit comprises an effective capacitance and an effective inductance that are in parallel or in series. In some embodiments, the effective inductance comprises a multiple winding coil of wire. A method that includes the steps of (i) providing a tank circuit and a phase qubit that are inductively coupled, (ii) reading out a state of the phase qubit, (iii) applying a flux to the phase qubit that approaches a net zero flux, (iv) increasing a level of flux applied to the phase qubit, and (v) observing a response of the tank circuit in a readout device.