Influence of Magnetic Field on Dark States in Transport through Triple Quantum Dots

Abstract

We theoretically study the electronic transport through a triple quantum dot system in triangular geometry weakly coupled to external metallic leads. By means of the real-time diagrammatic technique, the current and Fano factor are calculated in the lowest order of perturbation theory. The device parameters are tuned to such transport regime, in which coherent population trapping of electrons in quantum dots due to the formation of dark states occurs. The presence of such states greatly influences transport properties leading to a strong current blockade and enhanced, super-Poissonian shot noise. We consider both one-and two-electron dark states and examine the influence of magnetic field on coherent trapping in aforementioned states. When the system is in one-electron dark state, we observe a small shift of the blockade's region, whereas in the case of two-electron dark state, we show that strong magnetic field can lift the current blockade completely.

Berry‐Phase Effect in Single‐Molecule Magnets: Analytical and Numerical Results

“…The fingerprint of the Berry-phase effect in spin-molecule systems is determined by the suppression of tunnel splitting when different spin tunneling paths interfere destructively for certain values of the transverse magnetic field. [9][10][11] More recently, electron transport across a three-terminal SMM has been explored in various studies, and the Coulomb blockade has been demonstrated. The Kondo effect oscillations as a function of the transverse magnetic field have also been studied.…”

“…The fingerprint of the Berry‐phase effect in spin‐molecule systems is determined by the suppression of tunnel splitting when different spin tunneling paths interfere destructively for certain values of the transverse magnetic field. [ 9–11 ]…”