Effects of Transverse Magnetic Anisotropy on Current-Induced Spin Switching

TL;DR

This paper theoretically investigates how transverse magnetic anisotropy influences current-induced spin switching in magnetic adatoms and SMMs, highlighting the role of quantum tunneling and spin-valve effects in transport properties.

Contribution

It introduces a theoretical analysis of the impact of transverse anisotropy and quantum tunneling on spin switching and conductance in magnetic adatoms and SMMs.

Findings

Quantum tunneling of magnetization causes resonant peaks in spin and current.

Conductance depends on the relative orientation of spins, enabling spin control.

Resonant features are observable with ferromagnetic electrodes.

Abstract

Spin-polarized transport through bistable magnetic adatoms or single-molecule magnets (SMMs), which exhibit both uniaxial and transverse magnetic anisotropy, is considered theoretically. The main focus is on the impact of transverse anisotropy on transport characteristics and the adatom's/SMM's spin. In particular, we analyze the role of quantum tunneling of magnetization (QTM) in the mechanism of the current-induced spin switching, and show that the QTM phenomenon becomes revealed as resonant peaks in the average values of the molecule's spin and in the charge current. These features appear at some resonant fields and are observable when at least one of the electrodes is ferromagnetic. We also show that the conductance generally depends on the relative orientation of the average adatom's/SMM's spin and electrode's magnetic moment. This spin-valve like magnetoresistance effect can be used to control spin switching of the adatom's/SMM's spin.