Kinetic control of the current through a single molecule

Abstract

A unified description is put forward for the electron transmission through a molecule that is attached to two leads with the molecule being characterized by a single level to be populated by the transferred electrons. In deriving the expression for the current the Coulomb interaction is accounted for between the two extra electrons that may occupy the molecular level. The formation of two distinct transmission channels associated with the neutral and the singly charged molecule can directly be related to this interaction. Moreover, each transmission channel comprises a sequential as well as a direct (tunneling) pathway. The first pathway is realized via hopping transitions between the molecule and the neighboring electrodes. Just this inelastic kinetic process is responsible for the kinetic charging of the molecule. Then, the second pathway takes place against the background of kinetic molecular charging. In particular, it is demonstrated that hopping transmissions which are asymmetric with respect to the two electrodes cause a kinetic current rectification. The transient population of the molecule, realized by the transferred electrons, determines the rectification; the latter becomes rather large for resonant transmission.

Charge transmission through single molecules: Effects of nonequilibrium molecular vibrations and photoinduced transitions

“…It is a particular pleasure for one of the authors of this article (V.M.) to remind here on some common contributions to Molecular Electronics [4][5][6][7][8][9][10]. To come into contact of Peter Hänggi's particular interest and outstanding contributions to this field the results presented in the subsequent text, therefore, are related to the external field control of molecular junctions and the use of the density matrix theory to describe current flow through single molecules.…”

“…The equilibrium statistical operator for the first type of reservoir has been introduced in Eq. (9). The one for the thermal reservoir of secondary vibrational coordinates follows as the canonical statistical operator defined by H sm .…”

“…This is the case if the transferred electrons spent a time-interval in the molecule comparable to the characteristic time of vibrational relaxation. Now, the use of master equations governing molecular state populations is appropriate for the computation of IV-characteristics (see [9,[18][19][20][21][22][23][24][25][26][27][28][29]). …”

Molecular Diode at Fast Switching on (off) Regime

“…1). Similar single-level models are often used to clarify the physics of charge transmission through organic molecules [8][9][10][11][12][13][14][15].…”

External field control of charge transmission through single molecules: Switching effects and transient currents

“…The approach is well suited to study the case of direct charge transmission through the molecule. If charge transmission proceeds in a sequential way including intermediate state relaxation subsequent current formation is best described by master equations governing molecular state populations [12][13][14][15][16][17][18][19][20][21][22][23][24]. In particular, all the studies underlined the need to account for non-equilibrium vibrational distributions in the molecule.…”