Magnetic field switching in parallel quantum dots

TL;DR

This paper demonstrates that magnetic flux can switch off current in parallel quantum dots due to Coulomb blockade, with a sharp dependence on flux quantum multiples and divergence in relaxation time.

Contribution

It reveals a novel flux-dependent current switching mechanism in parallel quantum dots caused by Coulomb blockade effects.

Findings

Current is blocked for all flux values except integer multiples of flux quantum.

The current dependence on flux is non-analytic and exhibits a sharp switch.

Relaxation time diverges as flux approaches integer multiples of flux quantum.

Abstract

We show that the Coulomb blockade in parallel dots pierced by magnetic flux $\Phi$ completely blocks the resonant current for any value of $\Phi$ except for integer multiples of the flux quantum $\Phi_0$. This non-analytic (switching) dependence of the current on $\Phi$ arises only when the dot states that carry the current are of the same energy. The time needed to reach the steady state, however, diverges when $\Phi\to n\Phi_0$.