arXiv subjects

Natalia Noginova

Publications and source records attributed to Natalia Noginova.

6 recordsLinked to original sources

arXiv2026

Plasmon drag and photoinduced magnetic effects in plasmonic and magnetic metals

Photoinduced electric effects in plasmonic and magnetic materials under pulsed laser illumination exceed the prediction of the electromagnetic momentum-transfer mechanism by orders of magnitude. In order to get more information on the nature of the effect we study the kinetics of photovoltages in permalloy thin films at different photoexcitation configurations. The photoinduced electric signals consist of magnetically dependent and magnetically independent components which are of significant magnitude and mainly follow the temporal profile of the laser pulse. In contrast, the predicted contribution from the Anomalous Nernst Effect is much weaker and exhibits substantially slower kinetics. These observations suggest that ultrafast photoexcited hot electrons, rather than thermal mechanisms, play the dominant role in generating the observed photovoltage.

cond-mat.mtrl-sci↗

arXiv2020

Magnetically dependent plasmon drag in permalloy structures

Significant photovoltages are observed in permalloy grating-like structures in response to pulsed laser light illumination. Electric signals are enhanced at plasmon resonance conditions and show a clear dependence on the magnetic field with a characteristic hysteresis. Estimations show that the effect could not be explained solely by the laser-induced heating. Alternative mechanisms are discussed.

physics.optics↗

arXiv2017

Spin Angular Momentum Transfer and Plasmogalvanic Phenomena

We introduce the continuity equation for the electromagnetic spin angular momentum (SAM) in matter and discuss the torque associated with the SAM transfer in terms of effective spin forces acting in a material. In plasmonic metal, these spin forces result in plasmogalvanic phenomenon which is pinning the plasmon-induced electromotive force to atomically-thin layer at the metal interface.

cond-mat.mtrl-sci↗

arXiv2016

Electron magnetic resonance in magnetic nanoparticles: dependence on the particle size and applicability of the modified giant spin model

Superparamagnetic nanoparticles containing hundreds and thousands of coupled electron spins are on the boundary between classical and quantum behavior, and demonstrate features which are typical for paramagnetic spins and absent in macroscopic ferromagnetic systems. In order to better understand the evolution of magnetization dynamics from quantum to classical behavior with the increase in the system size, we study the electron magnetic resonance signal in suspensions of iron oxide nanoparticles as the function of the particle size. The experimental data are compared with numerical simulations based on the giant spin approach.

cond-mat.mes-hall↗

arXiv2016

On Nature of Plasmon Drag Effect

Light-matter momentum transfer in plasmonic materials is theoretically discussed in the framework of plasmonic pressure mechanism taking into account non-equilibrium electron dynamics and thermalization process. We show that our approach explains the experimentally observed relationship between the plasmon-related electromotive force and absorption and allows one to correctly predict the magnitude of the plasmon drag emf in flat metal films. We extend our theory to metal films with modulated profiles and show that the simple relationship between plasmonic energy and momentum transfer holds at relatively small amplitudes of height modulation and an approximation of laminar electron drift. Theoretical groundwork is laid for further investigations of shape-controlled plasmon drag in nanostructured metal.

physics.optics↗

arXiv2014

Spontaneous emission of electric and magnetic dipoles in the vicinity of thin and thick metal

Strong modification of spontaneous emission of Eu3+ ions placed in close vicinity to thin and thick gold and silver films was clearly demonstrated in a microscope setup separately for electric and magnetic dipole transitions. We have shown that the magnetic transition was very sensitive to the thickness of the gold substrate and behaved distinctly different from the electric transition. The observations were described theoretically based on the dyadic Green's function approach for layered media and explained through modified image models for the near and far-field emissions. We established that there exists a "near-field event horizon", which demarcates the distance from the metal at which the dipole emission is taken up exclusively in the near field.

cond-mat.mtrl-sci↗