Half-integer Shapiro-steps in superconducting qubit with a π-Josephson junction

Half-integer Shapiro steps at the 0-pi crossover of a ferromagnetic Josephson junction.

We investigate the current-phase relation of S/F/S junctions near the crossover between the 0 and the pi ground states. We use Nb/CuNi/Nb junctions where this crossover is driven both by thickness and temperature. For a certain thickness a nonzero minimum of critical current is observed at the crossover temperature. We analyze this residual supercurrent by applying a high frequency excitation a...

Half-Integer Shapiro Steps at the 0- Crossover of a Ferromagnetic Josephson Junction

257005-1 We investigate the current-phase relation of S=F=S junctions near the crossover between the 0 and the ground states. We use Nb=CuNi=Nb junctions where this crossover is driven both by thickness and temperature. For a certain thickness a nonzero minimum of critical current is observed at the crossover temperature. We analyze this residual supercurrent by applying a high frequency excita...

Superconducting pi qubit with a ferromagnetic Josephson junction.

Solid-state qubits have the potential for the large-scale integration and for the flexibility of layout for quantum computing. However, their short decoherence time due to the coupling to the environment remains an important problem to be overcome. We propose a new superconducting qubit which incorporates a spin-electronic device: the qubit consists of a superconducting ring with a ferromagneti...

Shapiro steps in Josephson Junctions

We use Ginzburg-Landau theory to describe the phase transition to the superconducting state and the current through a superconductor. Applying quantum mechanics to the Josephson junction following Feynmann’s method the Josephson relations for AC and DC current through the junctions is obtained. The resistively shunted Josephson junction and the resistively and capacitively shunted Josephson jun...

Shapiro Steps in BSCCO Intrinsic Josephson Junctions