title: A versatile setup for ultrafast broadband optical spectroscopy of coherent collective modes in strongly correlated quantum systems.
abstract: A femtosecond pump-probe setup is described that is optimised for broadband transient reflectivity experiments on solid samples over a wide temperature range. By combining high temporal resolution and a broad detection window, this apparatus can investigate the interplay between coherent collective modes and high-energy electronic excitations, which is a distinctive characteristic of correlated electron systems. Using a single-shot readout array detector at frame rates of 10 kHz allows resolving coherent oscillations with amplitudes <10-4. We demonstrate its operation on the charge-transfer insulator La2CuO4, revealing coherent phonons with frequencies up to 13 THz and providing access into their Raman matrix elements.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Baldini
authors.affiliation: Laboratory for Ultrafast Microscopy and Electron Scattering and the Lausanne Centre for Ultrafast Science , IPHYS, Station 6, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Mann
authors.affiliation: Laboratory for Ultrafast Microscopy and Electron Scattering and the Lausanne Centre for Ultrafast Science , IPHYS, Station 6, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Simone
authors.initials: S
authors.lastname: Borroni
authors.affiliation: Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science , ISIC, Station 6, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Christopher
authors.initials: C
authors.lastname: Arrell
authors.affiliation: Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science , ISIC, Station 6, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Frank
authors.initials: F
authors.lastname: van Mourik
authors.affiliation: Laboratory for Ultrafast Microscopy and Electron Scattering and the Lausanne Centre for Ultrafast Science , IPHYS, Station 6, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Carbone