Microscopic Current Dynamics in Nanoscale Junctions

Abstract

So far transport properties of nanoscale contacts have been mostly studied within the static scattering approach. The electron dynamics and the transient behavior of current flow, however, remain poorly understood. We present a numerical study of microscopic current flow dynamics in nanoscale quantum point contacts. We employ an approach that combines a microcanonical picture of transport with time-dependent density-functional theory. We carry out atomic and jellium model calculations to show that the time evolution of the current flow exhibits several noteworthy features, such as nonlaminarity and edge flow. We attribute these features to the interaction of the electron fluid with the ionic lattice, to the existence of pressure gradients in the fluid, and to the transient dynamical formation of surface charges at the nanocontact-electrode interfaces. Our results suggest that quantum transport systems exhibit hydrodynamical characteristics which resemble those of a classical liquid.

8 pages, 5 figures; Accepted for publication in Phys. Rev. B

References in corpus (3)

• Dynamical corrections to the DFT-LDA electron conductance in nanoscale systems
• Tunneling through nanosystems: Combining broadening with many-particle states
• Approach to steady state transport in nanoscale conductors

Cited by in corpus (5)

• Stochastic Time-Dependent Current-Density-Functional Theory
• Stroboscopic wavepacket description of non-equilibrium many-electron problems
• Ab-initio formulation of the 4-point conductance of interacting electronic systems
• Turbulence-induced magnetic flux asymmetry at nanoscale junctions
• Reply to Comment on "Dynamical corrections to the DFT-LDA electron conductance in nanoscale systems"