Polarization selectivity of charge localization induced by 7-fs nearly single-cycle light-field in an organic metal

TL;DR

This study demonstrates that the polarization of a nearly single-cycle 7-fs light field can selectively induce charge localization in an organic metal, revealing polarization-dependent control of charge order in a triangular lattice system.

Contribution

It provides new insights into polarization-selective charge localization induced by ultrafast light fields in organic conductors, combining experimental and numerical approaches.

Findings

Charge order is efficiently induced when pump polarization is perpendicular to the CO axis.

Polarization dependence of transient reflectivity spectra reveals control over charge localization.

Numerical simulations confirm field-induced charge redistribution causes the observed effects.

Abstract

Polarization selectivity of light-field-induced charge localization was investigated in an organic metal alpha-(BEDT-TTF)2I3 with a triangular lattice. Dependences of transient reflectivity spectra on polarizations of the 7-fs pump and probe lights indicate that a short-range charge order (CO) is efficiently induced from the metallic phase for the pump polarization perpendicular to the 1010-type CO axis. Numerical solution of a time-dependent Schrodinger equation clarified that the 1010-CO is induced by field-induced re-distribution of charges cooperating with competing inter-site Coulomb repulsions in the triangular lattice.