PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstr. 111, 5232 Villigen PSI, Switzerland
Dynamic Quantum Materials Laboratory, École Polytechnique Fédérale de Lausanne, Station 12, 1015 Lausanne, Switzerland
Preparatory optics experiments, such as ultrafast proximate optical magnetometry (UPOM), will be conducted at DQML/EPFL.
THz pump – X-ray/THz probe experiments [e.g. using X-ray diffraction, resonant inelastic X-ray scattering, or X-ray magnetic circular dichroism (XMCD)] will mainly take place at SwissFEL, but potentially also other FEL facilities worldwide.
Duration: 3 years
Domain: Matter and Materials, Future technologies
Description:
Nonthermal control of electronic properties using ultrafast light pulses is particularly suitable for the tuning of quantum materials where a (non-)resonant low-energy pump pulse can coherently drive ordered states and excitations.
Candidates are invited to develop a project to control properties, such as charge-density wave (CDW) order, as well as magnetic exchange and order, via THz or mid-infrared pulses with tailored space-time symmetries. Examples include chiral phonon control to alter the spin magnetization; two-color drives to induce inversion symmetry breaking, e.g. of CDW order, and off-resonant Floquet engineering of magnetic exchange.
The groundwork for this type of control, e.g. the availability of bandwidth-tunable circularly polarized and multi-frequency THz pulses, has already been laid at DQML. Those capabilities will be adapted for use at large-scale facilities, such as SwissFEL. After initial optical characterization at DQML, hard and/or soft X-ray FEL pulses will be used to investigate the induced dynamics. Mirroring pump capabilities at DQML and SwissFEL will allow for true multi-messenger probing, such as combining UPOM with XMCD to measure both macroscopic and microscopic ultrafast magnetization dynamics.
The project will be supervised by the two hosts and conducted in collaboration with other SwissFEL scientists and the PSI Condensed Matter Theory Group.