New magneto-transport phenomena have been discovered in magnetic multilayers and are now being optimized for industrial applications, extending the conventional electronics with new functionality. However, most of the current research on magnetic multilayer materials and its device applications rely on conventional equilibrium electron transport. The full potential of nano-structuring, which leads to a broad spectrum of novel non-equilibrium transport phenomena, is therefore not realized. In this research project we will focus on practically unexplored functional principles that can be implemented in nanostructures produced by state-of-the-art lithography and surface manipulation techniques. Our main idea is to use electrically controlled spin currents in highly non-equilibrium regimes with respect to energy and temperature; hence "spin-thermo-electronics". The large amount of heat generated in nanoscale devices is today one of the most fundamental obstacles for reducing the size of electronics. In this proposal we turn the problem around by instead using electrically controlled local heating of magnetic nano-circuits to achieve fundamentally new functionality, relevant to several key objectives of the information and communication technology. Particular emphasis will be put on investigating and technologically evaluating the interplay of spin, charge, and heat in magnetic structures of sub-10 nm dimensions. Such structures, although inaccessible by today's lithographic means, are in our view crucial for further miniaturization of electronic devices.