Charge Density Wave Materials Probed in Time and Momentum Space

Enrico Da Como
University of Bath
S3 Seminar Room, 3rd floor, Physics Building
Marco Gibertini (FIM, UNIMORE) and Claudia Cardoso (S3, CNR-NANO)

Charge density wave phenomena involving periodic electronic charge order in solids are common in low dimensional quantum-materials. They arise from a delicate balance of electron-electron and electron-phonon interactions. The interest in understanding these systems comes from the associated metal to insulator transitions with potential applications in switching devices and memristors. In this talk, I will present our recent research efforts in offering an accurate description of the electronic structure. In particular, combining angle resolved photoemission spectroscopy and band structure T-TaSe2 [1,2]. In addition, by performing experiments with time resolution <100 fs, I will explain how coherent phonon oscillations seen in the band structure allow for an estimation of the anharmonic potential characterizing the amplitude mode of the CDW condensate [3]. The results are a step forward in the understanding of CDW physics in TaSe2 compounds and towards establishing time- and momentum-resolved photoemission as valuable methods for quantum materials.

[1] Sayers, C. J.; Hedayat, H.; Ceraso, A.; Museur, F.; Cattelan, M.; Hart, L. S.; Farrar, L. S.; Dal Conte, S.; Cerullo, G.; Dallera, C.; et al. Phys. Rev. B 2020, 102 (16), 161105.
[2] Sayers, C.Phys. Rev. Lett. 2023, 130 (15), 156401.

[3] Sayers, C.; Cerullo, G.; Zhang, Y.; Sanders, C. E.; Chapman, B.; Wyatt, A. S.; Springate, E.; Wolverson, D.; Da Como, E.; Carpene, E. Under Review 2023.