UNI-MB - logo
UMNIK - logo
 
E-viri
Recenzirano Odprti dostop
  • Implementation of supercond...
    Oboznov, V. A; Ryazanov, V. V; Balashov, D; Zorin, A. B; Khabipov, M; Koshelets, V. P; Ustinov, A. V; Rossolenko, A. N; Lisenfeld, J; Bol'ginov, V. V; Poletto, S; Dmitriev, P. N; Feofanov, A. K

    Nature physics, 08/2010, Letnik: 6, Številka: 8
    Journal Article

    High operation speed and low energy consumption may allow the superconducting digital single-flux-quantum circuits to outperform traditional complementary metal-oxide-semiconductor logic. The remaining major obstacle towards high element densities on-chip is a relatively large cell size necessary to hold a magnetic flux quantum Φ0. Inserting a π-type Josephson junction in the cell is equivalent to applying flux Φ0/2 and thus makes it possible to solve this problem. Moreover, using π-junctions in superconducting qubits may help to protect them from noise. Here we demonstrate the operation of three superconducting circuits-two of them are classical and one quantum-that all utilize such π-phase shifters realized using superconductor/ferromagnet/superconductor sandwich technology. The classical circuits are based on single-flux-quantum cells, which are shown to be scalable and compatible with conventional niobium-based superconducting electronics. The quantum circuit is a π-biased phase qubit, for which we observe coherent Rabi oscillations. We find no degradation of the measured coherence time compared to that of a reference qubit without a π-junction.