Abstract-Phase-resolved two-dimensional terahertz spectroscopy including off-resonant interactions beyond the χ(3) limit

Carmine Somma1, Giulia Folpini1, Klaus Reimann1, Michael Woerner1,a) and Thomas Elsaesser1


1 Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
a) Electronic mail: woerner@mbi-berlin.de
J. Chem. Phys. 144, 184202 (2016); http://dx.doi.org/10.1063/1.4948639

http://scitation.aip.org/content/aip/journal/jcp/144/18/10.1063/1.4948639

We present the first two-dimensional (2D) terahertz (THz) experiment with three phase-locked THz pulses and a fully phase-resolved detection of the nonlinearly emitted field by electrooptic sampling. In a prototype experiment we study the ultrafast dynamics of nonlinear two-phonon and two-photon interbandcoherences in the narrow-gap semiconductor InSb. Due to the extraordinarily large optical interband dipole of InSb the experiments were performed in the strongly nonperturbative regime of light-matter interaction allowing for impulsive off-resonant excitation of both two-phonon coherences and two-photoninterband coherences, the ultrafast dynamics of which is experimentally observed as a function of the waiting time in the three-pulse 2D experiment. Our novel three-pulse 2D THz spectroscopy paves the way for the detailed investigation of nonlinear quantum coherences in solids and holds potential for an extension to other systems.