Electric Control of Spin Supercurrents in Hybrid Rashba Structures

The digital economy ever-increasingly requires denser, faster and more energy-efficient data processing, but heat-dissipating ohmic losses limit further performance improvements. Superconducting electronics offers the potential to enhance magnetic memory and logic performance because readout can be achieved with record-low heat dissipation. Furthermore, intrinsic or interfacial spin-orbit coupling (SOC) can enable a thin-film superconductor to exceed the paramagnetic limit. For Rashba-type SOC, theory indicates that the superconducting thermodynamic properties of a finite-size thin film are strongly sample-size dependent due to the creation of edge states: for example, for a geometrically anisotropic thin film superconductor, the critical field can be tunable through the direction of an externally applied in-plane magnetic field. These findings open perspectives for the development of superconducting spin-orbitronic devices as well as superconducting structures in which the superconducting state can be controlled with an electric field. In this poster, we discuss our experimental results towards the development of a hybrid superconducting device in which Rashba-SOC and charge accumulation within a thin-film heavy metal (HM) can be tuned via an electric field and so control the superconducting transition of a proximity-coupled thin film superconductor. The electric field is applied to the HM via a ferroelectric lead magnesium niobate-lead titanate (PMN-PT) substrate.