O.S. Temnaya1, S.A. Nikitov2

1,2 Kotelnikov IRE of RAS (Moscow, Russia)

Problem formulating. Recently, many studies in the field of spintronics and magnonics have been devoted to creating functional elements, such as directional couplers, mode selectors, etc. [1, 2]. One of the most critical issues is searching for ways to control the intrinsic damping of spin waves in such structures. When the system consists of coupled structures, where the intrinsic damping is equally enhanced in one structure and compensated in the other one, the system is called PT-symmetric.

Goal. Investigate the conditions for the appearance of PT-symmetry in a system of coupled magnonic structures with equally balanced gain and loss of spin waves.

Result. We propose a PT-symmetric system of planar ferromagnet-normal metal structures coupled with magneto-dipolar interaction. A method for equivalent amplification and compensation of intrinsic damping of spin waves based on the spin Hall effect application is suggested. We demonstrate that increasing the distance between waveguides decreases the voltage of exceptional point appearance, and the coupling strength also decreases. We show that the studied system has a highly narrow resonant amplitude dependence on voltage, which shows the specific nature of the exceptional point. The resonance linewidth of the studied system is almost half of the spin-wave resonance linewidth of a partial HM/FM heterostructures.

Practical meaning. Results can be used to create high-precision devices using such as sensors and detectors.

Temnaya O.S., Nikitov S.A. PT-symmetric planar coupled magnonic ferromagnetic/normal metal. Nonlinear World. 2022.
V. 20. № 2. P. 43-47. DOI: https://doi.org/10.18127/j20700970-202202-09 (In Russian)

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