Coherent laser control of the current through molecular junctions

Abstract

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.

6 pages and 4 figures

References in corpus (7)

• Driven quantum transport on the nanoscale
• Current induced light emission and light induced current in molecular tunneling junctions
• The influence of ultra-fast laser pulses on electron transfer in molecular wires studied by a non-Markovian density matrix approach
• Shot noise in tunneling transport through molecules and quantum dots
• Shot noise control in ac-driven nanoscale conductors
• Switching the current through molecular wires
• Charge transport through a molecule driven by a high-frequency field

Cited by in corpus (2)

• Modeling elastic and photoassisted transport in organic molecular wires: length dependence and current-voltage characteristics
• Molecular electronics in junctions with energy disorder