arXiv subjects

Giorgos Livanas

Publications and source records attributed to Giorgos Livanas.

3 recordsLinked to original sources

arXiv2022

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

We investigate Josephson junctions among conventional superconducting wires, in the presence of externally applied Zeeman fields and supercurrents. We demonstrate that the critical Josephson current and the current-phase relation of the junction depends on the relative orientation of the applied Zeeman fields and supercurrents. The controllability of the Josephson current relies on the stabilization of conventional superconductivity in high magnetic fields, due to the restoration of the opposite momentum opposite spin projection resonance at the Fermi level. We assert that our results can lead to the development of novel superconducting electronics.

cond-mat.supr-con↗

arXiv2021

Majorana Zero Modes in Ferromagnetic Wires without Spin-Orbit Coupling

We present a novel controllable platform for engineering Majorana zero modes. The platform consists of a ferromagnetic metallic wire placed among conventional superconductors, which are in proximity to ferromagnetic insulators. We demonstrate that Majorana zero modes emerge localised at the edges of the ferromagnetic wire, due to the interplay of the applied supercurrents and the induced by proximity exchange fields with conventional superconductivity. Our mechanism does not rely on the pairing of helical fermions by combining conventional superconductivity with spin-orbit coupling, but rather exploits the misalignment between the magnetization of the ferromagnetic insulators and that of the ferromagnetic wire.

cond-mat.supr-con↗

arXiv2021

Platform for controllable Majorana zero modes using superconductor/ferromagnet heterostructures

We propose a novel platform for the creation and manipulation of Majorana zero modes consisting of a ferromagnetic metallic wire placed between conventional superconductors which are in proximity to ferromagnetic insulators. Our device relies on the interplay of applied supercurrents and exchange fields emerging from the ferromagnetic insulators. We assert that the proposed superconductor/ferromagnet heterostructures exhibit enhanced controllability, since topological superconductivity can be tuned apart from gate voltages applied on the ferromagnetic wire, also by manipulating the applied supercurrents and/or the magnetisation of the ferromagnetic insulators.

cond-mat.supr-con↗