Fano resonances of microwave structures with embedded magneto-dipolar quantum dots

Abstract

Articles you may be interested inSize dependent ferromagnetic resonance and magnetic anisotropy of hexagonal barium and strontium ferrite powders J. Appl. Phys. 113, 17E154 (2013); 10.1063/1.4801742 Fano antiresonance in electron transport through a parallel-coupled quantum-dot structure Transition between onion states and vortex states in exchange-coupled Ni -Fe ∕ Mn -Ir asymmetric ring dots J. Appl. Phys. 99, 08G303 (2006); 10.1063/1.2164435 Mesoscopic effects in quantum dots, nanoparticles and nuclei AIP Conf.Long range dipole-dipole correlation in a ferromagnetic sample can be treated in terms of collective excitations of the system as a whole. Ferrite samples with linear dimensions smaller than the dephasing length, but still much larger than the exchange-interaction scales, are mesoscopic structures. Recently, it was shown that mesoscopic quasi-2D ferrite disks, distinguishing by multiresonance magneto-dipolar-mode (MDM) spectra, demonstrate unique properties of artificial atomic structures: energy eigenstates, eigen power-flow vortices, and eigen helicity parameters. Because of these properties, MDMs in a ferrite disk enable the confinement of microwave radiation to subwavelength scales. In microwave structures with embedded MDM ferrite samples, one can observe quantized fields with topologically distinctive characteristics. The use of a quasi-2D ferrite-disk scatterer with internal MDM resonance spectra along the channel propagation direction could change the transmission dramatically. In this paper, we show that interaction of the MDM ferrite particle with its environment has a deep analogy with the Fano-resonance interference observed in natural and artificial atomic structures. We characterize the observed effect as Fano-resonance interference in MDM quantum dots. V C 2013 AIP Publishing LLC. [http://dx.

Magnetic-dipolar-mode Fano resonances for microwave spectroscopy of high absorption matter

“…Long radiative lifetimes of topologically singular MDMs combine strong subwavelength confinement of electromagnetic energy with a narrow spectral line width and may carry the signature of Fano resonances [39 -41]. It was shown [42] that interaction of the MDM ferrite particle with its environment has a deep analogy with the Fano-resonance interference observed in natural and artificial atomic structures. The aim of the present study is to show how the transition between symmetric Lorentzian and asymmetric Fano line shapes in microwave structures with MDM ferrite disks can be used for effective microwave spectroscopy.…”

Magnetic-Dipolar-Mode Oscillations for Near- And Far-Field Manipulation of Microwave Radiation

“…Specific long-distance topological properties of these fields are exhibited in the effects of path-dependent interference [22]. It was also shown that interaction of the MDM ferrite particle with its environment has a deep analogy with the Fano-resonance interference observed in natural and artificial atomic structures [23]. A ferrite is a magnetic dielectric with low losses.…”

“…An example of such a spectrum, studied in Ref. [23], is shown in Figure 2. The resonance modes are designated in succession by numbers n = 1, 2, 3, .…”

“…As volumes smaller than the wavelength are probed, measurements of optical energy become uncertain, highlighting the difficulty with performing measurements in this regime. The above analysis of energy eigenstates gives possibility for deeper understanding of the nature of the experimentally observed multiresonance spectra of microwave oscillations in a microwave cavity originated from a MDM ferrite disk [23,[39][40][41][42][43]. These spectra were obtained by varying a bias magnetic field at a constant operating frequency, which is a resonant frequency of the cavity.…”

“…This results in appearance of peculiar fields -the ME fields. The helicity parameters of ME fields give evidence for violation of Faraday law and, consequently, violation of Lorentz invariance [20][21][22][23].…”