# James E. Baumgardner, Odenton US

## James E. Baumgardner, Odenton, MD US

Patent application number | Description | Published |
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20090033369 | ARBITRARY QUANTUM OPERATIONS WITH A COMMON COUPLED RESONATOR - A quantum logic gate is formed from multiple qubits coupled to a common resonator, wherein quantum states in the qubits are transferred to the resonator by transitioning a classical control parameter between control points at a selected one of slow and fast transition speeds, relative to the characteristic energy of the coupling, whereby a slow transition speed exchanges energy states of a qubit and the resonator, and a fast transition speed preserves the energy states of a qubit and the resonator. | 02-05-2009 |

20090206871 | ARBITRARY QUANTUM OPERATIONS WITH A COMMON COUPLED RESONATOR - A quantum logic gate is formed from multiple qubits coupled to a common resonator, wherein quantum states in the qubits are transferred to the resonator by transitioning a classical control parameter between control points at a selected one of slow and fast transition speeds, relative to the characteristic energy of the coupling, whereby a slow transition speed exchanges energy states of a qubit and the resonator, and a fast transition speed preserves the energy states of a qubit and the resonator. | 08-20-2009 |

20090267635 | METHOD AND APPARATUS FOR HIGH DENSITY SUPERCONDUCTOR CIRCUIT - The disclosure relates to a method for providing a logic circuit element. The method includes arranging a series of Josephson junctions between a first Josephson junction and a second Josephson junction, the first Josephson junction having a first critical current (I | 10-29-2009 |

20090322374 | METHOD AND APPARATUS FOR CONTROLLING QUBITS WITH SINGEL FLUX QUANTUM LOGIC - In one embodiment, the disclosure relates to a method and apparatus for controlling the energy state of a qubit by bringing the qubit into and out of resonance by coupling the qubit to a flux quantum logic gate. The qubit can be in resonance with a pump signal, with another qubit or with some quantum logic gate. In another embodiment, the disclosure relates to a method for controlling a qubit with RSFQ logic or through the interface between RSFQ and the qubit. | 12-31-2009 |

20100033206 | METHOD AND APPARATUS FOR BALLISTIC SINGLE FLUX QUANTUM LOGIC - In one embodiment, the disclosure relates to a single flux quantum (SFQ) signal transmission line powered by an AC power source. The AC power source supplies power to a transformer having a primary winding and a secondary winding. The primary winding receives the AC signal and the secondary winding communicates the signal to the SFQ transmission line. The transmission line can optionally include an input filter circuit for receiving the incoming SFQ pulse. The filter circuit can have a resistor and an inductor connected in parallel. In an alternative arrangement, the filter circuit can comprise of an inductor. A first Josephson junction can be connected to the filter circuit and to the secondary winding. The Josephson junction triggers in response to the incoming SFQ pulse and regenerates a pulse signal in response to a power discharge from the secondary winding. | 02-11-2010 |

20100182039 | Quantum Gate Operations with a Common Coupled Resonator - Systems and methods are provided for performing a quantum gate operation. A first classical control parameter is associated with a first qubit and coupled to a resonator. The first classical control parameter is transitioned from a first control value to a second control value. The first classical control parameter is returned from the second control value to the first control value via an adiabatic sweep operation, as to permit a transfer of energy between the first qubit and the resonator that causes a change in the quantum state of the qubit and resonator. | 07-22-2010 |

20100207657 | Method and Apparatus for Ballistic Single Flux Quantum Logic - In one embodiment, the disclosure relates to a single flux quantum (SFQ) signal transmission line powered by an AC power source. The AC power source supplies power to a transformer having a primary winding and a secondary winding. The primary winding receives the AC signal and the secondary winding communicates the signal to the SFQ transmission line. The transmission line can optionally include an input filter circuit for receiving the incoming SFQ pulse. The filter circuit can have a resistor and an inductor connected in parallel. In an alternative arrangement, the filter circuit can comprise of an inductor. A first Josephson junction can be connected to the filter circuit and to the secondary winding. The Josephson junction triggers in response to the incoming SFQ pulse and regenerates a pulse signal in response to a power discharge from the secondary winding. | 08-19-2010 |

20100237899 | Method and Apparatus for Ballistic Single Flux Quantum Logic - In one embodiment, the disclosure relates to a single flux quantum (SFQ) signal transmission line powered by an AC power source. The AC power source supplies power to a transformer having a primary winding and a secondary winding. The primary winding receives the AC signal and the secondary winding communicates the signal to the SFQ transmission line. The transmission line can optionally include an input filter circuit for receiving the incoming SFQ pulse. The filter circuit can have a resistor and an inductor connected in parallel. In an alternative arrangement, the filter circuit can comprise of an inductor. A first Josephson junction can be connected to the filter circuit and to the secondary winding. The Josephson junction triggers in response to the incoming SFQ pulse and regenerates a pulse signal in response to a power discharge from the secondary winding. | 09-23-2010 |

20110133770 | METHOD AND APPARATUS FOR CONTROLLING QUBITS WITH SINGLE FLUX QUANTUM LOGIC - In one embodiment, the disclosure relates to a method and apparatus for controlling the energy state of a qubit by bringing the qubit into and out of resonance by coupling the qubit to a flux quantum logic gate. The qubit can be in resonance with a pump signal, with another qubit or with some quantum logic gate. In another embodiment, the disclosure relates to a method for controlling a qubit with RSFQ logic or through the interface between RSFQ and the qubit. | 06-09-2011 |

20110241765 | PHASE QUANTUM BIT - A phase quantum bit is disclosed. In one embodiment, the phase quantum bit may comprise a Josephson junction and a distributed element coupled to the Josephson junction. The distributed element provides a capacitive component and an inductive component of the phase quantum bit. | 10-06-2011 |

20120124432 | SYSTEM AND METHOD FOR PHASE ERROR REDUCTION IN QUANTUM SYSTEMS - One embodiment of the invention includes a quantum system. The system includes a superconducting qubit that is controlled by a control parameter to manipulate a photon for performing quantum operations. The system also includes a quantum resonator system coupled to the superconducting qubit and which includes a first resonator and a second resonator having approximately equal resonator frequencies. The quantum resonator system can represent a first quantum logic state based on a first physical quantum state of the first and second resonators with respect to storage of the photon and a second quantum logic state based on a second physical quantum state of the first and second resonators with respect to storage of the photon. | 05-17-2012 |

20120144159 | QUANTUM PROCESSOR - One embodiment of the invention includes a quantum processor system. The quantum processor system includes a first resonator having a first characteristic frequency and a second resonator having a second characteristic frequency greater than the first characteristic frequency. A qubit cell is coupled to each of the first resonator and the second resonator. The qubit cell has a frequency tunable over a range of frequencies including the first characteristic frequency and the second characteristic frequency. A classical control mechanism is configured to tune the frequency of the qubit cell as to transfer quantum information between the first resonator and the second resonator. | 06-07-2012 |

20120159272 | METHODS OF INCREASING FIDELITY OF QUANTUM OPERATIONS - Systems and methods are provided for improving fidelity of a quantum operation on a quantum bit of interest. A controlled quantum gate operation, controlled by the quantum bit of interest, id performed on an ancillary quantum bit. An energy state of the ancillary quantum bit is measured to facilitate the improvement of the fidelity of the quantum operation. | 06-21-2012 |

20140203838 | QUANTUM PROCESSOR - One embodiment of the invention includes a quantum processor system. The quantum processor system includes a first resonator having a first characteristic frequency and a second resonator having a second characteristic frequency greater than the first characteristic frequency. A qubit cell is coupled to each of the first resonator and the second resonator. The qubit cell has a frequency tunable over a range of frequencies including the first characteristic frequency and the second characteristic frequency. A classical control mechanism is configured to tune the frequency of the qubit cell as to transfer quantum information between the first resonator and the second resonator. | 07-24-2014 |