The Terahertz Side of Quantum Materials: From Nonequilibrium Control to Deep Sub-Wavelength Spectroscopy

19.06.2024 14:00 – 15:30

The remarkable properties of quantum materials originate from a delicate balance among many interacting degrees of freedom. External stimuli that perturb this precarious equilibrium can steer complex solids into entirely new phases, with novel functionalities and collective responses. Terahertz light plays a crucial role in this context, both in controlling and spectroscopically probing these materials.
In this talk, I will first show how the optical excitation of lattice vibrations with ultra-short and ultra-intense terahertz pulses can be used to induce or control broken-symmetry phases in quantum materials, such as quantum paraelectrics and magnetic insulators.
I will then present a terahertz microscope designed to address the challenges of spectroscopy for samples hundreds of times smaller than the wavelength, such as van der Waals devices. Demonstrated with bilayer graphene, our approach enables broadband terahertz spectroscopy of gate-tunable devices, bringing a critical tool for investigating correlated phases to the realm of microstructured quantum materials.

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Bâtiment: Datcha

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