Vibrational detection and control of spin in mixed-valence molecular transistors

TL;DR

This paper demonstrates how vibrational modes in mixed-valence molecular transistors can be used to detect and control the molecule's spin state through electron transport, without external magnetic fields.

Contribution

It introduces a method to detect and manipulate molecular spin states via vibrational effects and nonequilibrium transport in mixed-valence molecules, avoiding magnetic field use.

Findings

Vibrational modes enable spin detection through vibronic conductance peaks.

Spin states can be controlled via vibration-induced spin-blockade.

Distinct spin states produce identifiable conductance signatures.

Abstract

We investigate electron transport through a mixed-valence molecular complex in which an excess electron can tunnel between hetero-valent transition metal ions, each having a fixed localized spin. We show that in this class of molecules the interplay of the spins and the vibrational breathing modes of the ionic ligand-shells allows the total molecular spin to be detected as well as controlled by nonequilibrium transport. Due to a spin-dependent pseudo Jahn-Teller effect electronic transitions with different spin values can be distinguished by their vibronic conductance side peaks, without using an external magnetic field. Conversely, we show that the spin state of the entire molecule can also be controlled via the nonequilibrium quantized molecular vibrations due to a vibration-induced spin-blockade.