Super tunneling

Datum

13.12.2017

Zeit

09:30 - 10:30

Sprecher

Prof. Christian Joachim

Zugehörigkeit

GNS-CEMES-CNRS, 29 rue J. Marvig, 31055 Toulouse Cedex, France; MANA, National Institute for Material Sciences, 1-1 Namiki, Ibaraki, Japan; CFAED TU DRESDEN Grand Professor

Serie

TUD nanoSeminar

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien

Host

G. Cuniberti

Beschreibung

At low bias voltage and in its HOMO-LUMO energy gap interval, the conductance of a molecular wire decays exponentially while increasing its length. The same phenomenon occurs with a surface dangling bond atomic wire. The corresponding inverse decay length beta of this through bond tunneling phenomenon ranges for example from beta = 1.2 A^-1 for an alkane molecular wire to about beta = 0.2 A^-1 for a medium large HOMO-LUMO gap kappa conjugated molecular wire. As a function of kappa and of the effective mass m* of the tunneling electrons, beta varies following a universal monotonic decay law. For a given kappa we will discuss (1) what prevents beta to be exactly zero that is reaching what can be named a super tunneling transport regime, (2) how to approach a minimum beta value by a good choice of the chemical composition of the molecular wire.

Letztmalig verändert: 13.12.2017, 09:04:40