Measurement of Magnetization Dynamics in Single-Molecule Magnets Induced by Pulsed Millimeter-Wave Radiation

TL;DR

This study measures the rapid magnetization dynamics of single-molecule magnets under pulsed millimeter-wave radiation, revealing relaxation times on the order of 10 microseconds using inductive detection methods.

Contribution

It introduces a new experimental approach to observe fast spin dynamics in single-molecule magnets with pulsed microwave radiation.

Findings

Relaxation time of magnetization is about 10 microseconds.

Photon-induced magnetization dynamics occur on nanosecond to microsecond scales.

Heating effects are minimized compared to previous longer pulse experiments.

Abstract

We describe an experiment aimed at measuring the spin dynamics of the Fe8 single-molecule magnet in the presence of pulsed microwave radiation. In earlier work, heating was observed after a 0.2-ms pulse of intense radiation, indicating that the spin system and the lattice were out of thermal equilibrium at millisecond time scale [Bal et al., Europhys. Lett. 71, 110 (2005)]. In the current work, an inductive pick-up loop is used to probe the photon-induced magnetization dynamics between only two levels of the spin system at much shorter time scales (from ns to us). The relaxation time for the magnetization, induced by a pulse of radiation, is found to be on the order of 10 us.