Tunnel magneto-Seebeck effect

TL;DR

This paper reviews the development of the tunnel magneto-Seebeck (TMS) effect in magnetic tunnel junctions, highlighting experimental progress, material innovations, and theoretical insights since its discovery in 2011, with potential applications in nanoelectronics.

Contribution

It provides a comprehensive overview of the TMS effect, including experimental techniques, material design, and the integration of ab initio calculations with experiments for enhanced understanding.

Findings

Large TMS ratios observed in MTJs with half-metallic Heusler electrodes

Successful demonstration of TMS dependence on magnetic configuration

Advances in heating techniques and material engineering for TMS applications

Abstract

The interplay of charge, spin and heat transport is investigated in the fascinating research field of spin caloritronics, the marriage of spintronics and thermoelectrics. Here, many new spin-dependent thermal transport phenomena in magnetic nanostructures have been explored in the recent years. One of them is the tunnel magneto-Seebeck (TMS) effect in magnetic tunnel junctions (MTJs) that has large potential for future nanoelectronic devices, such as nanostructured sensors for three-dimentional thermal gradients, or scanning tunneling microscopes driven by temperature differences. The TMS describes the dependence of the MTJ's thermopower on its magnetic cofiguration when a thermal gradient is applied. In this review, we highlight the successful way from first observation of the TMS in 2011 to current ongoing developments in this research area. We emphasize on different heating techniques, material designs, applications, and additional physical aspects such as the role of the thermal conductivity of the barrier material. We further demonstrate the efficient interplay between ab initio calculations and experiments within this field, as this has led, e.g., to the detection of large TMS ratios in MTJs with half-metallic Heusler electrodes.