Proposal for a Nanoscale Superconductive Memory

Energy efficiency is a key issue for modern high performance computing. Superconductive digital electronics has already demonstrated superior performances in terms of speed and energy dissipations. However, there is still the open issue of the realization of effective sub-micron scale superconductive memories. Superconducting nanowires represent the state of the art of single photon detectors. Their technology has also been used to realize three-terminal active devices, where the output response is triggered by a current pulse. The combination of the electro-thermal mechanism of the nanowire and the magnetic coupling with a suitable material, can be used for the realization a nanowire-based memory device scalable to nanoscale. The principle of operation and material requirements are presented here. In particular the feasibility of the proposed device using EuS as magnetic material and NbN as nanowire is discussed. By using a physical model of the nanowire dynamics, in terms of the spatial distribution of electron and phonon temperatures, the feasibility of the proposed device has been verified, through numerical simulations. The device configurations considered have the specific goal of realizing reliable and high speed read and write operations, with the possibility of scalability to nanoscale.