Electric field tuning of magnetic states in single magnetic molecules

TL;DR

This paper introduces a novel mechanism for electric field control of magnetic states in single magnetic molecules by tuning spin superexchange interactions, demonstrated through first-principles calculations on transition metallic Porphyrins.

Contribution

It proposes a new method to enhance spin-electric coupling and flip spin states by tuning superexchange interactions, advancing molecular spintronics control.

Findings

Electric field can tune magnetic ground states in molecules.

Spin superexchange interactions are sensitive to electric fields.

Potential for designing electric-field-controlled molecular spintronic devices.

Abstract

Single magnetic molecules may be the smallest functional magnets. An electric-field controllable spin state of magnetic molecules is of fundamental importance for applications while its realization remains challenging. To date the observed spin-electric interaction based on spin-orbit coupling or spin dipole coupling is useful to tune fine spin structures but too weak to flip the spin state. In this work, we propose a new mechanism to realize enhanced spin-electric coupling and flip the spin states by tuning the spin superexchange between local spins. Using first-principles calculations and Heisenberg Hamiltonian, we demonstrate this effect in a family of magnetic molecules, transition metallic Porphyrins. We show that their d-{\pi} and {\pi}-{\pi} spin superexchange couplings are determined by the relative energies of d and {\pi} electronic states, which are sensitive to the applied electric field. Therefore, applying electric field can tune a wide range of magnetic ground states, including ferromagnetic, ferrimagnetic, and antiferromagnetic configurations. This spin-electric coupling may provide a new approach for designing and controlling molecular spintronics.