portrait portrait

DIPC–PAMS theory workshop

Towards reality in modelling of molecular electronics

June 13-17, 2016 ▪ Donostia-San Sebastián, Spain

Invited talk

Buttiker's probes in molecular electronics: Applications to charge and heat transport

Dvira Segal

Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, Canada M5S 3H6

The role of incoherent (elastic, inelastic) scattering effects on charge and heat conduction in molecules is explored using the phenomenological Buttiker's probe method. In the past 30 years this easy-to-implement approach has been extensively employed to research inelastic effects in the transport behavior of mesoscopic devices, yet limited to the linear response regime. Our recent work has been focused on extending this method to far-from-equilibrium applications. In a series of recent papers we showed that the probe technique can reliably mimic incoherent charge transfer phenomena under finite voltage biases [1-3], as well as vibrational heat conduction under large temperature differences [4-5].

Concerning incoherent electronic conduction, I will begin by defining two types of constructions, the dephasing and voltage probes. I will then show that these probes can properly reproduce the tunneling-to-hopping crossover in conductance at low applied bias [1]. At high bias, we will identify signatures of elastic and inelastic scattering processes in the electrical current [3], use Buttiker's probes to examine the robustness of tunneling diodes [2], and propose mechanisms for environmentally-induced diodes [3]. If time allows, I will discuss applications of Buttiker's probes in studies of vibrational heat transfer through molecules, placed under high temperature differences. I will particularly demonstrate the utility of the method in materializing nonlinear function, e.g., thermal diodes operating in the quantum regime [4-5].

[1] M. Kilgour and D. Segal, J. Chem. Phys. 143, 024111 (2015).

[2] M. Kilgour and D. Segal, J. Phys. Chem. C, 119, 25291 (2015).

[3] M. Kilgour and D. Segal, J. Chem. Phys. 144, 124107 (2016).

[4] D. Segal, Phys. Rev. E 79, 012103 (2009).

[5] M. Bandyopadhyay and D. Segal, Phys. Rev. E 84, 011151 (2011).