Pump-Probe Noise Spectroscopy of Molecular Junctions.
The slow response of electronic components in junctions limits the direct applicability of pump-probe type spectroscopy in assessing the intramolecular dynamics. Recently the possibility of getting information on a sub-picosecond time scale from dc current measurements was proposed. We revisit the idea of picosecond resolution by pump-probe spectroscopy from dc measurements and show that any intramolecular dynamics not directly related to charge transfer in the current direction is missed by current measurements. We propose a pump-probe dc shot noise spectroscopy as a suitable alternative. Numerical examples of time-dependent and average responses of junctions are presented for generic models.
Maicol A
MA
Ochoa
‡School of Chemistry, Tel-Aviv University, Tel Aviv 69978, Israel.
Yoram
Y
Selzer
§Schulich Faculty of Chemistry and the Lise Meitner Center for Computational Quantum Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel.
Uri
U
Peskin
Michael
M
Galperin
dc current; laser pulse pair sequence; molecule−contact interface; nonequilibrium Green function; shot noise