Condensed Matter Seminar, N. Peter Armitage, Johns Hopkins,"Shining (low frequency) light on quantum magnets: Ising spin chains, quantum spin ice, an

Mon, Feb 23, 2015, 1:15 pm to 2:30 pm
PCTS Seminar Room
Although typically we regard optical spectroscopies as probes of electronic degrees of freedom in materials, light's time-varying magnetic field allows one to couple to magnetic degrees of freedom. This talk will review recent advances in the area of time-domain THz spectroscopy and its application to “quantum" magnets. Our high signal to noise, routinely excellent energy resolution, and unique ability to measure complex response functions gives unique insight into the magnetic response of quantum materials and gives several distinct advantages in these matters over neutron scattering. I will give examples of the use of the technique on quantum magnet systems as diverse as 1D Ising spin chains, quantum spin ices, and spin-orbital liquids.