Group Seminar 2019/20
- Date
- Wednesday 9 October 2019, 14:00-15:00
- Location
- EC Stoner (7.70)
- Speaker
- Dr Chiara Ciccarelli
- Institution
- Cavendish Laboratory at the University of Cambridge
- Title
- Picosecond spin emission from antiferromagnets and ferrimagnets
- Category
- Group Seminar
The transfer of the magnetic information via spin currents is one of the building blocks of spintronics. This flow of angular momentum is enacted by spin-polarised charge currents in conductors and by pure spin-waves in insulators. Anti-ferromagnets have recently attracted much attention in spintronics for their favourable characteristics in the context of information storage technologies, such as fast switching times and zero stray fields. In anti-ferromagnets the magnetic moments are arranged in such a way to result in an overall zero magnetisation and it is an open question whether they can still act as efficient spin-emitters. In this talk I will describe the picosecond spin emission from a zero net-magnetisation spin source. In the first experiment, I will discuss how lattice sensitive optical excitation of spin polarised carriers in a disordered ferrimagnetic alloy with a compensation point leads to spin emission even when the overall magnetisation is zero. The second work is about spin pumping from an anti-ferromagnet by which the excitation of coherent modes at 1.2 THz results in the emission of a pure spin-current.