Shapiro like steps reveals molecular nanomagnets' spin dynamics

TL;DR

This paper introduces a method to detect the spin dynamics of a molecular nanomagnet by observing Shapiro-like steps in the Josephson junction's I-V characteristic, which are controlled by magnetic field parameters.

Contribution

It presents a novel approach to probe spin nutation in molecular nanomagnets using Josephson junctions and identifies the relationship between spin parameters and observable electrical features.

Findings

Shapiro-like steps appear in the I-V characteristic due to spin nutation.

Step widths and heights depend on nutation frequency and amplitude.

Magnetic fields tune the spin nutation parameters.

Abstract

We present an accurate way to detect spin dynamics of a nutating molecular nanomagnet by inserting it in a tunnel Josephson junction and studying the current voltage (I-V) characteristic. The spin nutation of the molecular nanomagnet is generated by applying two circularly polarized magnetic fields. We demonstrate that modulation of the Josephson current by the nutation of the molecular nanomagnet's spin appears as a stepwise structure like Shapiro steps in the I-V characteristic of the junction. Width and heights of these Shapiro-like steps are determined by two parameters of the spin nutation, frequency and amplitude of the nutation, which are simply tuned by the applied magnetic fields.