Dynamical magnetic anisotropy and quantum phase transitions in a vibrating spin-1 molecular junction

TL;DR

This paper investigates how mechanical stretching influences magnetic anisotropy and quantum phase transitions in a spin-1 molecular junction, revealing a tunable transition between non-Fermi and Fermi liquid phases driven by electron-vibron interactions.

Contribution

It demonstrates that vibrational modes induce effective anisotropy corrections, enabling control over quantum phases in spin-1 molecular devices, a novel insight into mechanically tunable quantum transport.

Findings

Electron-vibron coupling shifts ground state towards non-Fermi liquid phase.

Mechanical stretching can induce a transition to a Fermi liquid phase.

Numerical results show changes in conductance, spectral density, and susceptibility across the transition.

Abstract

We study the electronic transport through a spin-1 molecule in which mechanical stretching produces a magnetic anisotropy. In this type of device, a vibron mode along the stretching axis will couple naturally to the molecular spin. We consider a single molecular vibrational mode and find that the electron-vibron interaction induces an effective correction to the magnetic anisotropy that shifts the ground state of the device toward a non-Fermi liquid phase. A transition into a Fermi liquid phase could then be achieved, by means of mechanical stretching, passing through an underscreened spin-1 Kondo regime. We present numerical renormalization group results for the differential conductance, the spectral density, and the magnetic susceptibility across the transition.