Volume 79, Number 2, July 2007
|Number of page(s)
|Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
|04 July 2007
Coherent laser control of the current through molecular junctions
School of Engineering and Science, Jacobs University Bremen (Formerly International University Bremen.) - Campus Ring 1, 28759 Bremen, Germany
2 Institut für Physik, Technische Universität Chemnitz - 09107 Chemnitz, Germany
Accepted: 6 June 2007
The electron tunneling through a molecular junction modeled by a single site weakly coupled to two leads is studied in the presence of a time-dependent external field using a master equation approach. In the case of small bias voltages and high carrier frequencies of the external field, we observe the phenomenon of coherent destruction of tunneling, i.e. the current through the molecular junction vanishes completely for certain parameters of the external field. In previous studies the tunneling within isolated and open multi-site systems was suppressed; it is shown here that the tunneling between a single site and electronic reservoirs, i.e. the leads, can be suppressed as well. For larger bias voltages the current does not vanish any more since further tunneling channels participate in the electron conduction and we also observe photon-assisted tunneling which leads to steps in the current-voltage characteristics. The described phenomena are demonstrated not only for monochromatic fields but also for laser pulses and therefore could be used for ultrafast optical switching of the current through molecular junctions.
PACS: 73.63.Nm – Quantum wires / 03.65.Yz – Decoherence; open systems; quantum statistical methods / 33.80.-b – Photon interactions with molecules
© Europhysics Letters Association, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.