Pump-probe study of β’-(BEDT-TTF)(TCNQ) crystal near antiferromagnetic transition

Abstract

Abstract The photo-excited state properties of an organic Mott-insulator β’-(BEDT-TTF)(TCNQ) crystal were investigated by pump-probe measurements. Considerable change in the pump-probe reflection signal with a wide spectral range was observed near the antiferromagnetic (AF) transition temperature of the TCNQ layers. In the time response, approach to the AF temperature induced the appearance of a slow decay signal whose lifetime was estimated to be about 3 msec maximum. These results indicate that a sustained mechanism exists for photo-excited states near the AF transition, which is probably related to a critical slowing down phenomenon.