Optical Absorption Spectrum in YbCrO₃ under High Magnetic Field

Abstract

Optical absorption spectra of YbCrO₃ have been investigated by using a pulsed high magnetic field. As the magnetic field is increased along the a-axis of YbCrO₃ at 4.2 K, the energy position of the Cr³⁺ exciton—Yb³⁺ spin flip combined transition (R′ band) shifts to the higher energy side and its intensity becomes large. In the field region (H₀\gtrsim30 T) where the energy position of the R′ band approaches to that of the magnon sideband (Cr³⁺ exciton—Cr³⁺ magnon combined transition), the intensity of the R′ band increases by one or two orders of magnitude and then approaches to that of the magnon sideband. It was concluded that the noticeable increase of the intensity of R′ band under the magnetic field along the a-axis is attributed to the strong hybridization of the R′ band and the magnon sideband.