Control of the non-stationary spin-polarized tunneling currents by applied bias changing

TL;DR

This paper investigates how non-stationary bias changes influence spin-polarized tunneling currents in a single Anderson impurity system, revealing controllable spin dynamics and current inversion capabilities.

Contribution

It demonstrates that non-stationary characteristics and correlation functions can distinguish magnetic states and control spin-polarized currents via bias switching.

Findings

Non-stationary spin-polarized currents are generated during bias shifts.

Spin polarization and current direction can be inverted by bias changes.

Relaxation regimes and times are affected by bias switching.

Abstract

We reveal that for the single Anderson impurity localized between non-magnetic leads of the tunneling contact $"$magnetic$"$ state can be distinguished from the $"$paramagnetic$"$ one only by the analysis of the non-stationary system characteristics or the behavior of the second order correlation functions for the localized electrons occupation numbers. We investigate the response of the system to the sudden shift of the applied bias and to the switching $"$on$"$ the coupling to the second lead of the tunneling contact. We demonstrate that in addition to the changes of the relaxation regimes and typical relaxation time scales, non-stationary spin-polarized currents flowing in the both leads are present in the system. Spin polarization and direction of the non-stationary currents in each lead can be simultaneously inverted by the sudden changing of the applied bias voltage.