Carlo Vicario (SIMES Seminar)

Date(s) - Feb 16 2016
10:00 AM - 11:00 AM

Sycamore Room, Building 40, room 195


Strong-terahertz field effects in ferromagnet and semiconductors

Carlo Vicario
Paul Scherrer Institute, SwissFEL, Villigen-PSI, Switzerland

Recent developments in high field terahertz open new perspective for controlling optical, electronic and magnetic properties of matter on a sub-cycle timescale. In this talk I will present the high-power Terahertz source developments pursued at the Paul Scherrer Institute and discuss a scheme for confining the THz energy in diffraction-limited spot size and single-oscillation (socalled lambda-cubic volume) [1]. I will discuss furthermore, THz strong-field dynamics observed in semiconductors and magnetic thin films. Electric and magnetic fields reaching tens of MV/cm and several Tesla are used to manipulate ultrafast coherent spin dynamics and to change the optical properties of transparent materials on a sub-cycle timescale. As examples, I will present octavespanning spectral broadening by cross-phase-modulation and coherent magnetic dynamics [2]. Furthermore I will introduce 2-dimensional THz detectors based on CCD technology, which provides significantly higher spatial resolution, larger chip area and faster readout compared to the conventional THz imagers [3].


Fig. Large broadening of a laser spectrum triggered by strong THz field. The 2D map reports the laser abstractspectra (horizontal axis) at different delays with respect to the THz transient (vertical coordinates).

1. M. Shalaby, C. Vicario, C.P. Hauri, Nature Commun. doi: 10.1038/ncomms9439 (2015)
2. C.Vicario et al, Nature Photon. (2013) doi: 10.1038/NPHOTON.2013.209 (2013)
3. M. Shalaby, C.P. Hauri, Nature Commun. 6:5976 doi: 10.1038/ncomms6976 (2015)