Now out in Nature Materials! We show how phonon polaritons can be used to shrink the long wavelengths of terahertz (THz) light to UV wavelength scales. This record-high confinement is possible through new van der Waals materials called HfSe₂ and HfS₂ that possess an extreme light-matter coupling, opening a route toward miniaturized THz devices.

The project emerged from a collabroation between the groups of Josh Caldwell (Vanderbilt University, US), Alex Paarmann (FHI Berlin) and Lukas Eng (TU Dresden) with joint beam times at the free electron laser of the Helmholz Zentrum Dresden Rossendorf. It was fantastic to be part of this team!