Low Temperature Physics: 46, 830 (2020); https://doi.org/10.1063/10.0001550
Fizika Nizkikh Temperatur: Volume 46, Number 8 (August 2020), p. 984-990    ( to contents , go back )

Wannier–Stark ladder spectrum of Bloch oscillations of magneto-dipole spin waves in graded 1D magnonic crystals

E.V. Tartakovskaya

Institute of Magnetism NAS of Ukraine and MES of Ukraine, Kyiv 03142, Ukraine
E-mail: olena.tartakivska@gmail.com

A.S. Laurenson and V.V. Kruglyak

University of Exeter, Stocker Road, Exeter, EX4 4QL, United Kingdom
pos Анотація:

Received February 27, 2020, published online June 22, 2020

Abstract

We have used the method of Wannier functions to calculate the frequencies and profiles of spin waves localized in one-dimensional magnonic crystals due to a gradient in the bias magnetic field. This localization of spin waves is analogous to the phenomenon of Bloch oscillations of quantum-mechanical electrons in crystals in a uniform electric field. As a convenient yet realistic model, we consider backward volume magnetostatic spin waves in a film of yttrium-iron garnet in a bias magnetic field comprising spatially uniform, cosine and gradient contributions. The spin-wave spectrum is shown to have the characteristic form of a Wannier–Stark ladder. The analytical results are verified using those obtained using numerical micromagnetic simulations. The physics of spin-wave Bloch oscillations combines the topics of magnonic crystals and graded magnonic index — the two cornerstones of modern magnonics.

Key words: spin waves, Bloch oscillations, one-dimensional magnonic crystals.

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