The quantum behavior of Josephson junctions is often exploited to produce superconducting devices with outstanding performance. Josephson junctions can also be used in circuits that perform logic operations in picoseconds and may enable high-performance energy-efficient cryogenic computers, provided that cryogenic-compatible memory elements can be developed that can be switched by and integrated with superconducting logic circuits. Here, we show that the Josephson junctions based on pseudo-spin valve barriers could enable such memory elements by unambiguously discriminating the controlled changes in the Josephson coupling from the size-dependent remanent field effect. The underlying exchange field effect enables the nonvolatile switching of the Josephson coupling in its magnitude or phase, depending on the device structure. Because these switchable Josephson junctions can be scaled to submicrometer dimensions, they may enable the first high-performance, nonvolatile cryogenic memories as well as new phase-based circuit elements for superconducting electronics.
Citation: Nature Communications
Pub Type: Journals
Josephson junction, spin valve, cryogenic memory, superconducting electronics, spintronics