1301.2970 (P. Limelette et al.)

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

P. Limelette, V. Ta Phuoc, F. Gervais, R. Fresard

We report infrared spectroscopic properties of the strongly correlated layered cobalt oxide [BiBa$_{0.66}$K$_{0.36}$O$_2$]CoO$_2$. These measurements performed on single crystals allow us to determine the optical conductivity as a function of 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 damping scale as the temperature itself. In fact, a basic analysis demonstrates that this mode fully scales onto a function of $\omega$/T up to room temperature. This behavior suggests low energy excitations of non-Fermi liquid type originating from quantum criticality.

View original: http://arxiv.org/abs/1301.2970