Strong light-field effects driven by nearly single-cycle 7 fs light-field in correlated organic conductors

Abstract

We have demonstrated transient charge localization effects with a driving\nhigh-frequency field of 7-fs, 1.5-cycle near infrared light in correlated\norganic conductors. In a layered organic conductor alpha-(BEDT-TTF)2I3\n(BEDT-TTF: bis[ethylenedithio]-tetrathiafulvalene), a transient short-range\ncharge order (CO) state is induced in a metallic phase. In contrast to such\ndrastic change in the electronic state from the metal to the transient CO in\nalpha-(BEDT-TTF)2I3, dynamics of a field-induced reduction of a transfer\nintegral are captured as a red shift of the plasma-like reflectivity edge in a\nquasi-one-dimensional organic conductor (TMTTF)2AsF6 (TMTTF:\ntetramethyltetrathiafulvalene). These studies on the field-induced charge\nlocalization have been motivated by the theory of dynamical localization on the\nbasis of tight-binding models with no electron correlation under a strong\ncontinuous field. However, the results of pump-probe transient reflectivity\nmeasurements using nearly single-cycle 7-fs, 11 MV/cm pulses and the\ntheoretical studies which are presented in this review indicate that the pulsed\nfield contributes to the similar phenomenon with the help of a characteristic\nlattice structure and Coulomb repulsion.\n