Band-width control in a perovskite-type 3d^1 correlated metal Ca_1-xSr_xVO_3. II. Optical spectroscopy investigation

TL;DR

This study investigates how electron correlation strength affects optical properties in Ca_1-xSr_xVO_3 without changing electron count, revealing spectral weight redistribution without significant effective mass enhancement.

Contribution

It provides new insights into the optical spectra and electron correlation effects in a perovskite-type 3d^1 correlated metal near the Mott transition.

Findings

No critical effective mass enhancement observed.

Identification of anomalous features related to incoherent and coherent bands.

Large spectral weight redistribution occurs without large mass increase.

Abstract

Optical conductivity spectra of single crystals of Ca_1-xSr_xVO_3 have been studied to elucidate how the electronic behavior depends on the strength of the electron correlation without changing the nominal number of electrons per vanadium atom. The effective mass deduced by the analysis of the Drude-like contribution do not show critical enhancement, even though the system is close to the Mott transition. Besides the Drude-like contribution, two anomalous features were observed in the optical conductivity spectra of the intraband transition within the 3d band. These features can be assigned to transitions involving the incoherent and coherent bands near the Fermi level. The large spectral weight redistribution in this system, however, does not involve a large mass enhancement.