Voltage induced switching dynamics of a coupled spin pair in a molecular junction

TL;DR

This paper predicts that coupling magnetic molecules in a junction enables all-electrical control of spin states and current flow, with potential for enhanced or reduced current and rectification, avoiding magnetic fields or ferromagnetic contacts.

Contribution

It introduces a method for electrical control of molecular spin states through magnetic coupling, bypassing traditional magnetic field or contact methods.

Findings

Current can be significantly enhanced or suppressed by tuning exchange interactions.

Coupling enables electrical read/write of spin states without external magnetic fields.

Potential for current rectification based on molecular level alignment.

Abstract

Molecular spintronics is made possible by the coupling between electronic configuration and magnetic po- larization of the molecules. For control and application of the individual molecular states it is necessary to both read and write their spin states. Conventionally, this is achieved by means of external magnetic fields or ferromagnetic contacts, which may change the intentional spin state and may present additional challenges when downsizing devices. Here, we predict that coupling magnetic molecules together opens up possibilities for all electrical control of both the molecular spin states as well as the current flow through the system. Tuning between the regimes of ferromagnetic and anti-ferromagnetic exchange interaction, the current can be, at least, an order of magnitude enhanced or reduced. The effect is susceptible to the tunnel coupling and molecular level alignment which can be used to achieve current rectification.