Unidirectional Electronic Ring Current Driven by a Few Cycle Circularly Polarized Laser Pulse: Quantum Model Simulations for Mg−Porphyrin

• DOI: 10.1021/ja057197l
• Publication Date: 2006-05-24T04:51:44Z
• Authors: Ingo Barth; Jörn Manz; Yasuteru Shigeta; Kiyoshi Yagi
• Keywords: 0103 physical sciences; 01 natural sciences; 7. Clean energy

A circularly polarized ultraviolet (UV) laser pulse may excite a unidirectional valence-type electronic ring current in an oriented molecule, within the pulse duration of a few femtoseconds (e.g., tau = 3.5 fs). The mechanism is demonstrated by quantum model simulation for |X = |1(1)A(1g) --> |E(+) = |4 (1)E(u+) population transfer in the model system, Mg-porphyrin. The net ring current generated by the laser pulse (I = 84.5 microA) is at least 100 times stronger than any ring current, which could be induced by means of permanent magnetic fields, with present technology.