Lattice Dynamics
Lattice Dynamics
Research Group Alexander Paarmann
Research Group Alexander Paarmann

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Welcome to the Lattice Dynamics group website!

Our group is interested in optical phonons in polar dielectric crystals and their heterostructures. We use various linear and nonlinear mid-infrared to THz spectroscopy techniques, employing the Infrared Free Electron Laser (IR-FEL) at the FHI as an intense and tunable light source.

Using this unique laser, we study various problems ranging from infrared nanophotonics to phase transitions in complex oxides. Check out our research page and our recent publications for more information!

Switchable polariton-like waveguide modes
Jun 2019
Nikolai just submitted a paper (arXiv link) demonstrating s-polarized waveguide modes in thin films of a phase-change material on a polar dielectric substrate. These modes have very similar properties to “classical” surface phonon polaritons, thus opening up new opportunities for omnipolarized nanophotonics. Thanks to Thomas Taubner for this very productive collaboration. Cool stuff!
Crystal hybrids!
Jun 2019
Chris just had the Crystal hybrid paper accepted in ACS Nano after long struggle. Thanks to Josh Caldwell for this very intense (and eventually successful) collaboration! And: yay, Chris!
Epsilon-near-zero Berreman SHG!
Jun 2019
Nikolai just had his work on enhancement of second harmonic generation from phononic epsilon-near-zero Berreman modes accepted in ACS Photonics. Congrats, Niko!
Our first SFG microscope!
May 2019
Riko just submitted a paper (arXiv link) demonstrating long-wave infrared-visible sum-frequency generation microscopy for the first time. Great work, Riko!
It's a feature, not a ...
Apr 2019
Chris just published a paper on the low-temperature infrared dielectric function of hyperbolic α-quartz in Phys. Rev. B which was selected as Editor’s Suggestion! Congrats, Chris!