Two-level system fluctuators in superconducting devices have demonstrated coherent coupling with superconducting qubits. Here, we show that universal quantum logic gates can be realized in these two-level systems solely by tuning a superconducting resonator in which they are imbedded. Because of the large energy separation between the fluctuators, conventional gate schemes in the cavity QED approach that are widely used for solid-state qubits cannot be directly applied to the fluctuators. We study a scheme to perform the gate operations by exploiting the controllability of the superconducting resonator with realistic parameters. Numerical simulation that takes into account the decay of the resonator mode shows that the quantum logic gates can be realized with high fidelity at moderate resonator decay rate. The quantum logic gates can also be realized between fluctuators inside different Josephson junctions that are connected by a superconducting loop. Our scheme can be applied to explore the coupling between two-level system fluctuators and superconducting resonators as well as the coherent properties of the fluctuators.Two-level system fluctuators in superconducting devices have demonstrated coherent coupling with superconducting qubits. Here, we show that universal quantum logic gates can be realized in these two-level systems solely by tuning a superconducting resonator in which they are imbedded. Because of the large energy separation between the fluctuators, conventional gate schemes in the cavity QED approach that are widely used for solid-state qubits cannot be directly applied to the fluctuators. We study a scheme to perform the gate operations by exploiting the controllability of the superconducting resonator with realistic parameters. Numerical simulation that takes into account the decay of the resonator mode shows that the quantum logic gates can be realized with high fidelity at moderate resonator decay rate. The quantum logic gates can also be realized between fluctuators inside different Josephson junctions that are connected by a superconducting loop. Our scheme can be applied to explore the coupling between two-level system fluctuators and superconducting resonators as well as the coherent properties of the fluctuators.

arXiv:0903.0193Physical Review BApr 1, 20098 citations

Logic gates for superconducting qubits

Matthias Steffen, R. McDermott, Ken B. Cooper +7 more

Bulletin of the American Physical SocietyMar 22, 20050 citations

Quantum logic gates for superconducting resonator qudits

Frederick W. Strauch

We study quantum information processing using superpositions of Fock states in superconducting resonators as quantum $d$ -level systems (qudits). A universal set of single and coupled logic gates is theoretically proposed for resonators coupled by superconducting circuits of Josephson junctions. These gates use experimentally demonstrated interactions and provide an attractive route to quantum information processing using harmonic oscillator modes.We study quantum information processing using superpositions of Fock states in superconducting resonators as quantum $d$-level systems (qudits). A universal set of single and coupled logic gates is theoretically proposed for resonators coupled by superconducting circuits of Josephson junctions. These gates use experimentally demonstrated interactions and provide an attractive route to quantum information processing using harmonic oscillator modes.

arXiv:1108.2984Physical Review ANov 11, 201145 citations

Quantum gates for superconducting qubits

Chad T. Rigetti

Jan 1, 200910 citations

Measurement of 10 zJ energy dissipation of adiabatic quantum-flux-parametron logic using a superconducting resonator

Naoki Takeuchi, Yuki Yamanashi, Nobuyuki Yoshikawa

Adiabatic quantum-flux-parametron (AQFP) logic has the potential to operate with an ultimately small bit energy of several zeptojoules; however, this is too small to measure by conventional techniques. We measure such a small energy dissipation by coupling a superconducting resonator with an AQFP gate, where the insertion loss is sensitively varied with the small dissipation due to the very high Q factor of the resonator. We designed and implemented a 5 GHz superconducting resonator coupled with an AQFP gate. Measurement results show that the bit energy of the gate is ∼10 zJ at 5 GHz operation.Adiabatic quantum-flux-parametron (AQFP) logic has the potential to operate with an ultimately small bit energy of several zeptojoules; however, this is too small to measure by conventional techniques. We measure such a small energy dissipation by coupling a superconducting resonator with an AQFP gate, where the insertion loss is sensitively varied with the small dissipation due to the very high Q factor of the resonator. We designed and implemented a 5 GHz superconducting resonator coupled with an AQFP gate. Measurement results show that the bit energy of the gate is ∼10 zJ at 5 GHz operation.

Applied Physics LettersFeb 4, 201382 citations

Coupling superconducting qubits and resonators

Joel Strand

Bulletin of the American Physical SocietyFeb 29, 20120 citations

We study quantum information processing using superpositions of Fock states in superconducting resonators as quantum

d

-level systems (qudits). A universal set of single and coupled logic gates is theoretically proposed for resonators coupled by superconducting circuits of Josephson junctions. These gates use experimentally demonstrated interactions and provide an attractive route to quantum information processing using harmonic oscillator modes.