Stability of spintronic devices based on quantum ring networks

TL;DR

This paper investigates the stability of spintronic quantum ring networks under realistic conditions, showing they can maintain functionality despite errors, thermal effects, and scattering, with potential applications like spin filtering.

Contribution

It provides a detailed analysis of how quantum coherence-based spintronic devices perform under disorder and temperature, introducing designs resilient to these effects.

Findings

Devices tolerate moderate errors and scattering.

Thermal fluctuations can be mitigated with narrow energy input.

Proposed a network functioning as a narrow band energy filter.

Abstract

Transport properties in mesoscopic networks are investigated, where the strength of the (Rashba-type) spin-orbit coupling is assumed to be tuned with external gate voltages. We analyze in detail to what extent the ideal behavior and functionality of some promising network-based devices are modified by random (spin-dependent) scattering events and by thermal fluctuations. It is found that although the functionality of these devices is obviously based on the quantum coherence of the transmitted electrons, there is a certain stability: moderate level of errors can be tolerated. For mesoscopic networks made of typical semiconductor materials, even cryogenic temperatures can smear out the desired transport properties. When the energy distribution of the input carriers is narrow enough, it turns out that the devices can operate close to their ideal limits even at relative high temperature. As an example, we present results for two different networks: one that realizes a Stern-Gerlach device and another that simulates a spin quantum walker. Finally we propose a simple network that can act as a narrow band energy filter even in the presence of random scatterers.