Berry-phase blockade in single-molecule magnets

TL;DR

This paper investigates how Berry-phase interference affects electron transport in single-molecule magnets, revealing topological zeros in current when SMMs are placed between oppositely polarized leads, highlighting a new quantum transport phenomenon.

Contribution

It introduces a theoretical framework for understanding Berry-phase effects on electron tunneling in SMMs within the Coulomb blockade regime, emphasizing the role of lead polarization.

Findings

Detection of topological zeros in stationary current due to Berry-phase interference

Necessity of oppositely spin-polarized leads for observing spin tunneling effects

Identification of interference effects as a function of transverse magnetic field

Abstract

We formulate the problem of electron transport through a single-molecule magnet (SMM) in the Coulomb blockade regime taking into account topological interference effects for the tunneling of the large spin of a SMM. The interference originates from spin Berry phases associated with different tunneling paths. We show that in the case of incoherent spin states it is essential to place the SMM between oppositely spin-polarized source and drain leads in order to detect the spin tunneling in the stationary current, which exhibits topological zeros as a function of the transverse magnetic field.