Ultrafast and terahertz spintronics: Guest editorial

Spin-based electronics (spintronics) aims at extending electronic functionalities, which rely on the electron charge as information carrier, by spin of electron. To make spintronics competitive and compatible with other carriers like photons electrons, their speed needs to be pushed femtosecond time scales and, thus, terahertz frequencies. In ultrafast spintronics, optical electromagnetic pulses are used induce torque transport monitor subsequent evolution. The two approaches, sometimes referred femto-magnetism magnetism, have provided new, surprising, relevant insight well applications for spintronics. Examples include switching magnetic order generation broadband fields. This APL Special Topic Collection is dedicated provide a platform newest developments future trends in very active, dynamic, exciting research field