Spintronics is a prime example of how upstream research, with a lot of pioneer contributions done in Europe, can promptly lead to cutting-edge devices of vast commercial success. A prominent case is the use of Giant MagnetoResistance (GMR) in field sensors, which has led to an exponential increase in data storage capacity that has helped to foster the information revolution. Another example is the recent market introduction of a new generation of non-volatile magnetic memories based on magnetic tunnel junctions (MTJ), exploiting the Tunnel MagnetoResistance (TMR) and Spin Transfer Torque (STT) effects, which will challenge the ubiquity of existing semiconductor based memory devices such as DRAM and SRAM by offering lower power consumption and new paradigms for logic devices. In “classical” spintronics, most of the phenomena such as GMR, TMR or Spin Torques (and the related functionalities) are made possible through the exchange interaction between the conduction electron spins and local moments, which allow spin currents to be generated and nanomagnets to be controlled electrically.

A novel direction called Spin-Orbitronics exploits the relativistic Spin-Orbit (SO) interactions and opens fascinating new roads for basic research and new line of technologies, in which European Industries can take back the lead harnessing on the strength of the European academic research in this emerging topic with strong international competition.

This SO coupling, that is the relativistic correction to the equation of quantum physics can be significantly strong in materials or systems containing heavy atoms and lead to new interesting phenomena :

• The SO interactions are at the origin of a category of effects allowing an efficient conversions between charge and spin currents. Typical examples of SO effects are the spin Hall effect (SHE) (or Anomalous Hall effect in magnetic materials) by which a charge current can be converted into a transverse spin current and the inverse spin Hall effect (ISHE) for the inverse conversion. Such effects have already some technological relevance, for example with MRAMs of the 3-Terminal SO-MRAM type or the SO controlled DW based race track memory. Very recently, it it has been proved that a more efficient charge-spin conversion can be obtained by exploiting the SOC-induced properties of a two-dimensional electron gas (2DEG) at some surfaces and interfaces, the so-called Rashba interfaces and the surfaces or interfaces of new materials called topological insulators (TIs).  
• Another fascinating property of SO interaction is that it can be exploited to engineer magnetic materials in which new types of topological objects, such as the chiral domain walls or magnetic skyrmions can be stabilized. For example, it is anticipated that the topological protection of magnetic skyrmions should enhance their thermal stability that have a tunable dimension in the nm range, and consequently allow an easy manipulation by very small currents densities.

Combining these different spin-orbit related phenomena can lead to new and efficient ways for manipulating the magnetization in highly integrated spintronic devices with promising perspectives for the development a new generation of low power reconfigurable spintronic storage and/or logic devices.