Tobias Kamprath (Special Seminar)

Date(s) - Feb 6 2014
11:00 AM - 12:00 PM

Shasta Room, Bldg. 40, Room 361


How to use terahertz pulses to probe and control spin dynamics in solids

 Tobias Kampfrath

Department of Physical Chemistry, Fritz Haber Institute Berlin

 Terahertz (THz) electromagnetic radiation is a useful tool for probing and even controlling low-energy excitations such as phonons and Cooper pairs. This talk deals with two recent applications of THz spectroscopy in the field of spintronics. First, the magnetic field of an intense THz pulse is used to control the dynamics of a 1-THz magnon in the textbook-type antiferromagnet NiO. Such control may pave the way to an ultrafast switching of spin states. Second, ultrafast spin currents are injected from a ferromagnetic into a nonmagnetic metal. We show that the spin flow and the inverse spin Hall effect result in the emission of a THz pulse, thereby allowing us to monitor the spin transport. Furthermore, choosing nonmagnetic layers of different electron mobility permits manipulation of the shape of the spin pulse.