Spin-bias driven magnetization reversal and nondestructive detection in a single molecular magnet

TL;DR

This paper theoretically investigates magnetization reversal in a single molecular magnet driven by spin bias, revealing avalanche dynamics, hysteresis control via gate voltage, and a nondestructive detection method through polarized current measurement.

Contribution

It introduces a microscopic mechanism for spin-bias driven reversal and proposes a nondestructive detection technique based on polarized current response.

Findings

Reversal occurs via avalanche dynamics at the reversal point.

Hysteresis loops are tunable by gate voltage and temperature.

Nondestructive measurement of the SMM's spin orientation is feasible.

Abstract

The magnetization reversal in a single molecular magnet (SMM) weakly coupled to an electrode with spin-dependent splitting of chemical potentials (spin bias) is theoretically investigated by means of the rate equation. A microscopic mechanism for the reversal is demonstrated by the avalanche dynamics at the reversal point. The magnetization as a function of the spin bias shows hysteresis loops tunable by the gate voltage and varying with temperature. The nondestructive measurement to the orientation of giant spin in SMM is presented by measuring the fully polarized electric current in the response to a small spin bias. For Mn$_{12}$ac molecule, its small transverse anisotropy only slightly violates the results above. The situation when there is an angle between the easy axis of the SMM and the spin quantization direction of the electrode is also studied.