Electrically Switchable Ferromagnetic Josephson Junctions

这个超导自旋电子学的实验项目将研究铁磁超导约瑟夫森结中的自旋扭矩。在4.2K下工作的超导计算机已经被提出用来解决大规模计算的能量使用问题，作为神经形态计算机的部件，以及在毫克尔文温度下的量子计算机操作员和传统的室温电子学之间的接口。虽然在这样的4.2k计算机中实现逻辑的技术已经很好地建立了，但仍然没有合适的技术来实现寄存器之外的低温存储器。该项目旨在通过开发物理和材料来实现基于铁磁约瑟夫森结的存储技术来满足这一需求。基于铁磁约瑟夫森结的存储器结合了传统磁阻RAM单元的磁存储能力和超导体的无耗散特性。与第一代MRAM设计一样，我们最初的铁磁约瑟夫森结设计依赖于外加磁场来设置结1-3的状态。在现代的MRAM单元中，通过利用自旋转移扭矩或自旋轨道扭矩来电改变磁状态来设置状态。到目前为止，还没有采取与超导结对应的同等步骤。

This experimental project in superconducting spintronics will study spin-torques in ferromagnetic superconducting Josephson Junctions. Superconducting computers operating at 4.2K have been proposed to solve the problems of energy usage by large-scale computing, as components for a neuromorphic computer and to interface between a quantum computer operator at millikelvin temperatures and conventional room temperature electronics. Whilst the technology to implement logic in such a 4.2K computer is well established, there remains, a yet, no suitable technology to implement cryogenic memory beyond registers. This project aims to address this need by developing the physics and materials to implement memory technologies based on ferromagnetic Josephson junctions. A ferromagnetic Josephson junction based memory combines the magnetic storage capabilities of a conventional magneto-resistive RAM cell with the dissipation- less nature of superconductors. As with the first generation of MRAM designs, our initial ferromagnetic Josephson junction designs rely on an applied field to set the state of the junction 1-3. In a modern MRAM cell, the state is set by making use of spin-transfer torque or spin-orbit torques to electrical change the magnetic state. To date, there has not been the equivalent step taken with the superconducting junction counterparts.