ω / T scaling of the optical conductivity in strongly correlated layered cobalt oxide

P. Limelette (1) , V. Ta Phuoc (1) , François Gervais (1) , R. Fresard (2)

1 GREMAN - UMR 7347 - GREMAN (matériaux, microélectronique, acoustique et nanotechnologies)
2 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

We report infrared spectroscopic properties of the strongly correlated layered cobalt oxide [BiBa0.66K0.36O2]CoO2. These measurements, performed on single crystals, allow us to determine the optical conductivity as a function of the temperature. In addition to a large temperature-dependent transfer of spectral weight, an unconventional low-energy mode is found. We show that both its frequency and its damping scale as the temperature itself. In fact, a basic analysis demonstrates that this mode fully scales onto a function of ω/T up to room temperature. This behavior suggests low-energy excitations of non-Fermi liquid type originating from quantum criticality.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

P. Limelette, V. Ta Phuoc, François Gervais, R. Fresard. ω / T scaling of the optical conductivity in strongly correlated layered cobalt oxide. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2013, 87 (3), pp.035102. ⟨10.1103/physrevb.87.035102⟩. ⟨hal-01870100⟩