TY - JOUR
T1 - Nonmechanical conductance switching in a molecular tunnel junction
AU - Baratz, Adva
AU - Baer, Roi
PY - 2012/2/16
Y1 - 2012/2/16
N2 - We present a molecular junction composed of a donor (polyacetylene strands) and an acceptor (malononitrile) connected together via a benzene ring and coupled weakly to source and drain electrodes on each side, for which a gate electrode induces intramolecular charge transfer, switching reversibly the character of conductance. Using a new brand of density functional theory, for which orbital energies are similar to the quasiparticle energies, we show that the junction displays a single, gate-tunable differential conductance channel in a wide energy range. The gate field must align parallel to the displacement vector between donors and acceptor to affect their potential difference; for strong enough fields, spontaneous intramolecular electron transfer occurs. This event radically affects conductance, reversing the charge of carriers, enabling a spin-polarized current channel. We discuss the physical principles controlling the operation of the junction and find interplay of quantum interference, charging, Coulomb blockade, and electron-hole binding energy effects. We expect that this switching behavior is a generic property for similar donor-acceptor systems of sufficient stability.
AB - We present a molecular junction composed of a donor (polyacetylene strands) and an acceptor (malononitrile) connected together via a benzene ring and coupled weakly to source and drain electrodes on each side, for which a gate electrode induces intramolecular charge transfer, switching reversibly the character of conductance. Using a new brand of density functional theory, for which orbital energies are similar to the quasiparticle energies, we show that the junction displays a single, gate-tunable differential conductance channel in a wide energy range. The gate field must align parallel to the displacement vector between donors and acceptor to affect their potential difference; for strong enough fields, spontaneous intramolecular electron transfer occurs. This event radically affects conductance, reversing the charge of carriers, enabling a spin-polarized current channel. We discuss the physical principles controlling the operation of the junction and find interplay of quantum interference, charging, Coulomb blockade, and electron-hole binding energy effects. We expect that this switching behavior is a generic property for similar donor-acceptor systems of sufficient stability.
UR - http://www.scopus.com/inward/record.url?scp=84857522506&partnerID=8YFLogxK
U2 - 10.1021/jz201562a
DO - 10.1021/jz201562a
M3 - Article
AN - SCOPUS:84857522506
SN - 1948-7185
VL - 3
SP - 498
EP - 502
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 4
ER -