Vectorial Control of Magnetization by Light

TL;DR

This paper demonstrates a novel method for full two-dimensional control of magnetization vectors in solids using polarization-twisted femtosecond laser pulses, advancing ultrafast magnetic manipulation techniques.

Contribution

It introduces a new approach for vectorial control of magnetization via Raman-type nonlinear optical processes with independently steered degenerate modes.

Findings

Successful 2D magnetic oscillation control in NiO

Use of polarization-twisted pulses to manipulate magnetic vectors

Establishment of a new concept for light-induced magnetization control

Abstract

Coherent light-matter interactions have recently extended their applications to the ultrafast control of magnetization in solids. An important but unrealized technique is the manipulation of magnetization vector motion to make it follow an arbitrarily designed multi-dimensional trajectory. Furthermore, for its realization, the phase and amplitude of degenerate modes need to be steered independently. A promising method is to employ Raman-type nonlinear optical processes induced by femtosecond laser pulses, where magnetic oscillations are induced impulsively with a controlled initial phase and an azimuthal angle that follows well defined selection rules determined by the materials' symmetries. Here, we emphasize the fact that temporal variation of the polarization angle of the laser pulses enables us to distinguish between the two degenerate modes. A full manipulation of two-dimensional magnetic oscillations is demonstrated in antiferromagnetic NiO by employing a pair of polarization-twisted optical pulses. These results have lead to a new concept of vectorial control of magnetization by light.