Controllable critical Josephson current and 0-π transition in superconductor-insulator-superconductor heterostructures.

The intriguing electromagnetic properties of superconductors have led to the development of novel electronic devices which minimize energy dissipation, such as the energy-efficient rapid flux quantum logic devices. However, their broad implementation in classical computing setups is hindered by the absence of compatible memory units. To date, several variations of magnetic Josephson junctions have been proposed which, however, exhibit high switching time.

We propose a novel approach for realizing energy-efficient memory units with low switching time, compatible with already developed superconducting electronics. Our setup consists of conventional superconductor-insulator-conventional superconductor heterostructures, i.e. Josephson junctions, where supercurrents and magnetic fields are externally applied. Manipulating the relative orientation of the applied supercurrents and/or magnetic fields allows us to control the critical Josephson current and the 0-π transition of the Josephson junction. The insulating link among the two conventional superconductors quarantees the high normal phase resistance of the junction, corresponding to low switching time.