Direct observation of collective modes coupled to molecular orbital-driven charge transfer

ISHIKAWA, TADAHIKO; HAYES, STUART A.; KESKIN, SERCAN; CORTHEY, GASTÓN; HADA, MASAKI; PICHUGIN, KOSTYANTYN; MARX, ALEXANDER; HIRSCHT, JULIAN; SHIONUMA, KENTA; ONDA, KEN; OKIMOTO, YOICHI; KOSHIHARA, SHIN-YA; YAMAMOTO, TAKASHI; CUI, HENGBO; NOMURA, MITSUSHIRO; OSHIMA, YUGO; ABDEL-JAWAD, MAJED; KATO, REIZO; DWAYNE MILLER, R.J.

SCIENCE

AMER ASSOC ADVANCEMENT SCIENCE

Año: 2015 vol. 350 p. 1501 - 1505

0036-8075

Correlated electron systems can undergo ultrafast photoinduced phase transitions involving concerted transformations of electronic and lattice structure. Understanding these phenomena requires identifying the key structural modes that couple to the electronic states.We report the ultrafast photoresponse of the molecular crystal Me4P[Pt(dmit)2]2, which exhibits a photoinduced charge transfer similar to transitions between thermally accessible states, and demonstrate how femtosecond electron diffraction can be applied to directly observe the associated molecularmotions. Even for such a complex system, the key large-amplitudemodes can be identified by eye and involve a dimer expansion and a librational mode.The dynamics are consistent with the time-resolved optical study, revealing how the electronic, molecular, and lattice structures together facilitate ultrafast switching of the state.