Low-energy interband transition in the infrared response of the correlated metal SrVO3 in the ultraclean limit

Non-Fermi-liquid behavior of correlated metals is one of the central problems in condensed matter physics. To advance the understanding of the non-Fermi-liquid phase, it is crucial to know the intrinsic electronic response of correlated metals. The authors study the optical response of an archetypal correlated metal SrVO${}_{3}$ in the ultraclean limit. The results reveal that interband transitions can give rise to a significant contribution to the low-energy electronic response, mimicking the non-Fermi-liquid behavior of the charge dynamics.