Publication
Ultrafast multidimensional spectroscopy with field resolution and noncollinear geometry at mid-infrared frequencies
Publisher:
IOP Publishing
Date:
02-2022
DOI:
10.1088/1367-2630/AC4A16
Abstract: Energetic correlations and their dynamics govern the fundamental properties of condensed matter materials. Ultrafast multidimensional spectroscopy in the mid infrared is an advanced technique to study such coherent low-energy dynamics. The intrinsic many-body phenomena in functional solid-state materials, in particular few-layer s les, remain widely unexplored to this date, because complex and weak s le responses demand versatile and sensitive detection. Here, we present a novel setup for ultrafast multidimensional spectroscopy with noncollinear geometry and complete field resolution in the 15–40 THz range. Electric fields up to few-100 kV cm −1 drive coherent dynamics in a perturbative regime, and an advanced modulation scheme allows to detect nonlinear signals down to a few tens of V cm −1 entirely background-free with high sensitivity and full control over the geometric phase-matching conditions. Our system aims at the investigation of correlations and many-body interactions in condensed matter systems at low energy. Benchmark measurements on bulk indium antimonide reveal a strong six-wave mixing signal and map ultra-fast changes of the band structure with access to litude and phase information. Our results pave the way towards the investigation of functional thin film materials and few-layer s les.