Accessing electromagnetic properties of matter with cylindrical vector beams

Abstract

Cylindrical vector beam (CVB) is a structured lightwave characterized by its topologically nontrivial nature of the optical polarization. The unique electromagnetic field configuration of CVBs has been exploited to optical tweezers, laser accelerations, and so on. However, use of CVBs in research fields outside optics such as condensed matter physics has not progressed. In this paper, we propose potential applications of CVBs to those fields based on a general argument on their absorption by matter. We show that pulse azimuthal CVBs around terahertz or far-infrared frequencies can be a unique and powerful mean for time-resolved spectroscopy of magnetic properties of matter and claim that an azimuthal electric field of a pulse CVB would be a novel way of studying and controlling edge currents in topological materials. We also demonstrate how powerful CVBs will be as a tool for Floquet engineering of nonequilibrium states of matter.

High-harmonic generation by electric polarization, spin current, and magnetization

“…In addition to this, various experimental studies of THz-wave driven magnetic phenomena have been done: intense THz-laser driven magnetic resonance in an antiferromagnet 43,45 , magnon resonances in multiferroic magnets with the electric field of THz wave or laser [46][47][48] , spin control by THzlaser driven electron transitions 49 , dichroisms driven by THz vortex beams in a ferrimagnet 50 , etc. These experimental studies have stimulated theorists in many fields of condensed-matter physics, and as a result, several ultrafast magnetic phenomena driven by THz or GHz waves have been proposed and predicted: THz-wave driven inverse Faraday effect 51,52 , Floquet engineering of magnetic states such as chirality ordered states 53 and a spin liquid state 54 , applications of topological light waves to magnetism [55][56][57][58] , control of exchange couplings in Mott insulators with low-frequency pulses 59,60 , optical control of spin chirality in multiferroic materials 61 , and rectification of dc spin currents in magnetic insulators with THz or GHz waves 62,63 . Very recently, Takayoshi et al 64 numerically calculate the HHG spectra in quantum spin models, assuming that the applied THz laser is extremely strong beyond the current technique.…”

Theory for shift current of bosons: Photogalvanic spin current in ferrimagnetic and antiferromagnetic insulators

“…Typical results are the following: Magnetization switching by a circularly-polarized laser in ferrimagnets [16][17][18][19], laser-driven demagnetization [20][21][22], the spin pumping by gigahertz (GHz) or terahertz (THz) waves [23,24], focused-laser driven magnon propagation [25,26], intense THz-laser driven magnetic resonance [27,28], spin control by THz-laser driven electron transitions [29], dichroisms driven by THz vortex beams [30], angular momentum transfer between photons and magnons in cavities [31][32][33][34][35], a ultrafast detection of spin Seebeck effect [36], a phonon-mediated spin dynamics with THz laser [37], etc. Moreover, recent theoretical works have proposed several ways of optical control of magnetism: THz-wave driven inverse Faraday effect [38,39], Floquet engineering of magnetic states such as chirality ordered states [40,41] and a spin liquid state [42], generation of magnetic defects with laser-driven heat [43,44], applications of topological light waves to magnetism [44][45][46][47], control of exchange couplings in Mott insulators with high- [48] and low-frequency [49] waves, optical control of spin chirality in multiferroic materials [50], rectification of dc spin currents in magnetic insulators with electromagnetic waves [51][52]…”

Generation and decomposition of scalar and vector modes carrying orbital angular momentum: a review

“…The exploration of CVB capabilities is still largely limited to optical physicists and has recently been used as a tool to access electromagnetic properties of matter, including a novel way of studying and controlling edge currents in topological materials and for Floquet engineering of nonequilibrium states of matter. 149 In addition to the spatial variation in the SoP, it is possible to modify the phase front of the optical beam either independently or together. In the first situation, the wavefront can be made helical or in some alternate shape determined by a polynomial or special mathematical functional form.…”