News Reports
Jan 2022

Figure: A gap suppresses the particle-hole transitions. In contrast, all channels are available in the metallic phase.
A combined experimental and theoretical study of relaxation dynamics in the charge-density-wave system TbTe3 shows, how a dynamical insulator-to-metal transition affects fundamental interactions, such as electron-electron and electron-phonon scattering. Time- and angle-resolved photoemission spectroscopy utilizes optical excitation to transiently alter the energy gap and reveals a concurrent, highly unusual transient modulation of the relaxation rates of excited photocarriers.
State-of-the-art calculations [more...]
State-of-the-art calculations [more...]
Laurenz Rettig: rettig@fhi-berlin.mpg.de
Oct 2021

Figure: © Jörg Harms, MPSD. In the singlet exciton fission process, a singlet exciton (blue) is created upon absorbing light and then splits into two triplets (red) on ultrafast timescales. We have investigated the structural dynamics accompanying this process.
Singlet exciton fission (SEF) is a process occurring in several organic semiconductors by which an electronically excited singlet exciton spontaneously splits into two triplet excitons. The SEF properties, such as yields and rates, depend crucially on the molecular structure and intermolecular interactions. This calls for an experimental technique that can probe the structural changes accompanying the SEF process at the relevant time and length scales.
In a study published in Science Advances, we [more...]
In a study published in Science Advances, we [more...]