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Liubov Ivzhenko

Publications and source records attributed to Liubov Ivzhenko.

4 recordsLinked to original sources

Attached Split Ring Resonator Cavity for Magnon Photon Coupling

We present a chip scale planar cavity platform based on an attached split ring resonator (ASRR) integrated with yttrium iron garnet (YIG) structures to achieve strong magnon photon coupling in a compact hybrid system. The ASRR geometry was numerically optimized by tuning inter ring spacing, gap width, substrate thickness, and permittivity, resulting in a quality factor of Q = 190 at 5.48 GHz, enabling strong microwave magnetic field confinement and reduced radiative losses. The optimized cavity was coupled to YIG elements of three geometries: full ring, half ring, and disk. Full electromagnetic simulations show that the full ring geometry exhibits balanced performance with coupling strength 115 MHz and cooperativity 13.10, while the half ring shows a comparable coupling strength of 108 MHz and slightly higher cooperativity 13.50, despite edge induced demagnetizing effects. In contrast, the disk geometry couples at lower bias magnetic fields and achieves the strongest interaction (135 MHz, 25.30), enabled by improved microwave magnetic field overlap. These results demonstrate that geometry, rather than magnetic volume alone, is a key design parameter for tailoring magnon photon coupling, providing a practical framework for lithography compatible, on chip hybrid magnonic and quantum devices.

cond-mat.mtrl-sci

Influence of photon-magnon coupling to enhance spin-wave excitation

One of the main challenges in magnonics is the efficiency of the conversion of microwave signals into spin waves. This efficiency is low due to the significant mismatch between microwave and spin wave wavelengths in the GHz range $10^{-2}$ m and $10^{-8}$ m, respectively, leading to high energy consumption in magnonic circuits. To address this issue, we propose an approach based on a planar inverse split-ring resonator (ISRR) loaded with a nanometer-thick Py film and exploiting the photon-magnon coupling effect. Our numerical studies show that the ISRR-based antenna achieves more than a fourfold improvement in conversion efficiency compared to a conventional single microstrip transmission line at frequencies and bias magnetic fields around the anti-crossing frequency gap. This has been demonstrated in the weak photon-magnon coupling regime for the nanometer-thin permalloy film with micrometer lateral dimensions. Further optimization of the ISRR can help to achieve the strong coupling regime, making the system potentially useful for quantum technology. Our compact and efficient antenna design offers a significant advantage over standard microstrip lines, paving the way for scalable and powerful magnonic circuits for microwave signal processing.

cond-mat.mes-hall

Edge modes in 1D microwave photonic crystal

The microstrip of modulated width is a realization of a one-dimensional photonic crystal operating in the microwave regime. Like any photonic crystal, the periodic microstrip is characterised by the presence of frequency bands and band gaps that enable and prohibit wave propagation, respectively. The frequency bands for microstrip of symmetric unit cell can be distinguished by $0$ or $π$ Zak phase. The sum of these topological parameters for all bands below a given frequency gap determines the value of the surface impedance and whether or not edge modes are present at the end of the microstrip. We demonstrate that edge modes are absent in a finite microstrip terminated at both ends in the centres of unit cells, but they can be induced by adding the defected cells. Edge modes present at both ends of the microstrip enable microwave tunneling with high transitivity in the frequency gap with or without a change in phase. This has been demonstrated experimentally and developed in detail using numerical simulations and model calculations. The investigated system, with a doublet of edge modes in the frequency gap, can be considered as a narrow passband filter of high selectivity.

physics.app-ph

Manipulation over Surface Waves in Bilayer Hyperbolic Metasurfaces: Topological Transition and Multidirectional Canalization

Spoof surface plasmon-polariton is a type of surface wave propagating at the artificially engineered structures in microwave and terahertz ranges. These surface waves are highly important in planar photonic and on-chip devices, integrated circuits, lenses, sensors, and antennas applications. However, it is still a challenge to control the propagation regime of such surface waves including the wavefront shapes and propagation directions. In this letter, we study the surface waves in bilayer hyperbolic metasurfaces and show that interplay between two layers allows to manage their regime of propagation. We demonstrate the switching between angle and number of propagation directions of surface waves at the same frequency. Finally, we demonstrate experimentally the tunable multidirectional in-plane canalization of surface waves by adjusting directions of their propagation with angular range from 0 to 12.8 degrees. The discovered rotation-mediated interlayer coupling of hyperbolic metasurfaces paves way towards efficient in-plane transfer of localized electromagnetic signal.

physics.optics