Designer switches: Effect of crystal planes on time-dependent electron transport through an interacting quantum dot

TL;DR

This study investigates how the crystal planes of gold contacts influence the time-dependent electron transport in a quantum dot, revealing that different crystal orientations significantly affect transient current behavior.

Contribution

It demonstrates that crystal plane orientation of electrodes drastically impacts transient electron transport in quantum dots, a novel insight for nanoscale device design.

Findings

Transient conductance shows complex fluctuations depending on crystal planes.

Fluctuation frequencies relate to density of states features and Fermi level.

Different crystal planes lead to markedly different transient currents.

Abstract

The time-dependent non-crossing approximation is utilized to determine the effects of the crystal planes of gold contacts on time dependent current through a quantum dot suddenly shifted into the Kondo regime via a gate voltage. For an asymmetrically coupled system, instantaneous conductance exhibits complex fluctuations. We identify the frequencies participating in these fluctuations and they turn out to be proportional to the separation between the sharp features in the density of states and the Fermi level in agreement with previous studies. Based on this observation, we predict that using different crystal planes as electrodes would give rise to drastically different transient currents which can be accessed with ultrafast pump-probe techniques.