Influence of the doping concentration of Y1−yCayBa2Cu3O7−δ drain-source channels on the properties of superconducting field-effect devices

Influence of the doping concentration of YBa2u3O7-δ drain-source channels on the properties of superconducting field-effect devices / J. Mannhart ... – In: Applied physics letters. 83. 2003. S. 3528-353

Half-h/2e critical current-oscillations in SQUIDs

The current-voltage characteristics of Superconducting Quantum Interference Devices (SQUIDs) are known to modulate as a function of applied magnetic field with a period of one flux quantum $\Phi_0=h$/2e. Here we report on the fabrication and properties of SQUIDs modulating with a fundamental period of $1/2\times\Phi_0$. The characteristics of these bicrystal SQUIDs are consistent with either a strong sin(2φ) component of the current-phase relation of the Josephson current, or with an interaction between the Cooper pairs, causing an admixture of quartets to the condensate