Patent application number | Description | Published |
20080258753 | SYSTEMS, METHODS AND APPARATUS FOR ANTI-SYMMETRIC QUBIT-COUPLING - Apparatus, articles and methods relate to anti-symmetric superconducting devices for coupling superconducting qubits. | 10-23-2008 |
20100148853 | SYSTEMS, DEVICES, AND METHODS FOR CONTROLLABLY COUPLING QUBITS - A system for communicably coupling between two superconducting qubits may include an rf-SQUID coupler having a loop of superconducting material interrupted by a compound Josephson junction and a first magnetic flux inductor configured to controllably couple to the compound Josephson junction. The loop of superconducting material may be positioned with respect to a first qubit and a second qubit to provide respective mutual inductance coupling therebetween. The coupling system may be configured to provide ferromagnetic coupling, anti-ferromagnetic coupling, and/or zero coupling between the first and second qubits. The rf-SQUID coupler may be configured such that there is about zero persistent current circulating in the loop of superconducting material during operation. | 06-17-2010 |
20110018612 | SYSTEM, DEVICES AND METHODS FOR COUPLING QUBITS - A ladder structure is ferromagnetically coupled to a first qubit where the ladder structure has a monostable energy potential in use, such that the first qubit and the ladder structure effectively operate as a single qubit. The ladder structure and first qubit may be coupled via a superconducting flux coupler. The ladder structure may be a chain of at least two ferromagnetically coupled ladder elements. A value for each ladder element may be less than about 1. | 01-27-2011 |
20110060780 | SYSTEMS, METHODS, AND APPARATUS FOR CALIBRATING, CONTROLLING, AND OPERATING A QUANTUM PROCESSOR - Quantum annealing may include applying and gradually removing disorder terms to qubits of a quantum processor, for example superconducting flux qubits of a superconducting quantum processor. A problem Hamiltonian may be established by applying control signals to the qubits, an evolution Hamiltonian established by applying disorder terms, and annealing by gradually removing the disorder terms. Change in persistent current in the qubits may be compensated. Multipliers may mediate coupling between various qubits and a global signal line, for example by applying respective scaling factors. Two global signal lines may be arranged in an interdigitated pattern to couple to respective qubits of a communicatively coupled pair of qubits. Pairs of qubits may be communicatively isolated and used to measure a response of one another to defined signals. | 03-10-2011 |
20110065585 | SYSTEMS, METHODS AND APPARATUS FOR MEASURING MAGNETIC FIELDS - SQUIDs may detect local magnetic fields. SQUIDS of varying sizes, and hence sensitivities may detect different magnitudes of magnetic fields. SQUIDs may be oriented to detect magnetic fields in a variety of orientations, for example along an orthogonal reference frame of a chip or wafer. The SQUIDS may be formed or carried on the same chip or wafer as a superconducting processor (e.g., a superconducting quantum processor). Measurement of magnetic fields may permit compensation, for example allowing tuning of a compensation field via a compensation coil and/or a heater to warm select portions of a system. A SQIF may be implemented as a SQUID employing an unconventional grating structure. Successful fabrication of an operable SQIF may be facilitated by incorporating multiple Josephson junctions in series in each arm of the unconventional grating structure. | 03-17-2011 |
20120023053 | SYSTEMS AND METHODS FOR QUANTUM COMPUTATION USING REAL PHYSICAL HARDWARE - Iterative approaches to quantum computation are described. Incongruities in the behavior of the various individual elements in a quantum processor may be managed by establishing a set of equivalent configurations for the elements of the quantum processor. The quantum processor is programmed and operated using each equivalent configuration to determine a set of solutions. The solutions are evaluated to determine a preferred solution that best satisfies at least one criterion. Furthermore, thermodynamic effects from operating a quantum processor at non-absolute zero temperature can cause the ground state to be the most probable state into which the system will settle. By running multiple iterations the ground state may be identified as the state with the most frequent reoccurrences. Alternatively, the energy of each unique state may be calculated and the state that corresponds to the lowest energy may be returned as the solution to the problem. | 01-26-2012 |
20130313526 | SYSTEMS, METHODS AND APPARATUS FOR ACTIVE COMPENSATION OF QUANTUM PROCESSOR ELEMENTS - Apparatus and methods enable active compensation for unwanted discrepancies in the superconducting elements of a quantum processor. A qubit may include a primary compound Josephson junction (CJJ) structure, which may include at least a first secondary CJJ structure to enable compensation for Josephson junction asymmetry in the primary CJJ structure. A qubit may include a series LC-circuit coupled in parallel with a first CJJ structure to provide a tunable capacitance. A qubit control system may include means for tuning inductance of a qubit loop, for instance a tunable coupler inductively coupled to the qubit loop and controlled by a programming interface, or a CJJ structure coupled in series with the qubit loop and controlled by a programming interface. | 11-28-2013 |
20140137571 | SYSTEMS AND METHODS FOR CRYOGENIC REFRIGERATION - Systems and methods for improving the performance of dilution refrigeration systems are described. Filters and traps employed in the helium circuit of a dilution refrigerator may be modified to improve performance. Some traps may be designed to harness cryocondensation as opposed to cryoadsorption. A cryocondensation trap employs a cryocondensation surface having a high thermal conductivity and a high specific heat with a binding energy that preferably matches at least one contaminant but does not match helium. Multiple traps may be coupled in series in the helium circuit, with each trap designed to trap a specific contaminant or set of contaminants. Both cryocondensation and cryoadsorption may be exploited among multiple traps. | 05-22-2014 |