Tip-enhanced TeRAhertz sPIntronic emitters to unravel ultrafaST nanoscale dynamics – TRAPIST

Whilst the boom in THz research is still far from filling the THz technology gap, imaging at the nanoscale and at sub-ps timescales is currently a hot topic in spectroscopic micro- and nano-scopy.  Since it can reveal THz dynamics and their spatial dispersion in a contactless manner, it is can provide a deeper understanding of THz excitations and unlock the limitations of under development novel THz devices. However, the diffraction at THz wavelength (˜ 50 ?m) strongly limits the spatial resolution of classical far-field microscopes, and the coupling and collecting of THz fields to near-field microscopes strongly limits their SNR. TRAPIST thus proposes an original and innovative solution based on spintronic technologies to unlock this SNR bottleneck in near-field spectrally broadband THz microscopes, which will reciprocally offer an exceptional tool to characterize novel type of spintronic and 2D THz devices.
 
OBJECTIVES:
TRAPIST will integrate nanoscale spintronic THz emitters (STE) in a scattering-type Scanning Near-field Optical Microscope (s-SNOM). For this purpose, TRAPIST is structured along three key objectives:
1) Mastering spectrally ultra-broadband, efficient, polarization-controllable and nanometric thin STEs using active spintronic interfaces.
2) Integrating STEs in a s-SNOM using 2 approaches, by (a) placing the nanoscale STE below the AFM tip, or by (b) integrating it directly on the tip offering innovative 3D THz nanospectroscopy;
3) Generating the very first hyperspectral images up to 15 THz of two hot topics in THz nanophotonics and spintronics: (a) THz plasmon dynamics in 2D materials and (b) THz magnon dynamics in antiferromagnetic and multiferroic nanostructures;
For this, TRAPIST capitalizes on previous key achievements from the project partners by exploiting the best performances of new types of STEs, developed commercial AFM tip-based s-SNOM and from the partners’ expertise in THz technologies, and spintronic and magnonic devices.

OUTCOME/IMPACT:
TRAPIST will have direct applied and fundamental outcomes. On the applied side, TRAPIST will develop spin-based near-field wideband microscope with record SNR. By proposing a direct integration of the STE in a mature SNOM technology, we anticipate a rapid increase of TRL during the frame of the project. This will enable the characterisation and the optimization of novel THz nanophotonic and spintronic devices, together with direct applications for reverse engineering processes. On the fundamental side, TRAPIST will provide new insights into the mechanisms of THz generation of STEs, both in 2D and 3D, as well as permitting novel investigations into THz dynamics of 2D (plasmons and phonons) and AFM materials (magnons, phonons and their hybridized quanta).
 
CONSORTIUM:
The TRAPIST project gathers a complementary team of experts in nanoscale spintronic (UMPhy/Thales) and THz technologies (IEMN, LPENS, Thales). The consortium masters all the required steps to achieve the TRAPIST objectives: growth and modeling of STEs at UMPhy/Thales, THz spectroscopy (LPENS) and near-field microscopy (IEMN), device integration (IEMN, Thales, UMPhy).