Magnetic insulator spintronics: from magnon spin currents to black holes
Magnons are the bosonic quanta of spin waves - oscillations in the magnetization direction in magnets. In this talk I will discuss recent developments in spintronics that concern magnon spin transport through magnetic insulators. In particular, I will focus on nanostructures that consist of magnetic insulators coupled to metallic reservoirs. These act as injectors and detectors of spin currents. After reviewing recent experimental results, e.g. on room-temperature long-distance spin transport, I will outline our current theoretical understanding of these systems. Based on this, I will discuss theoretical predictions for superfluid spin transport, topological spin transport, and spin transport in magnonic Mott insulators. Finally, I will outline our proposal for implementing black-hole horizons for magnons.