Magnetic field-controlled nanoscale spin-wave vertical directional coupler

TL;DR

This paper introduces a nanoscale spin-wave vertical directional coupler with over 99.5% efficiency, controllable by magnetic fields, enabling advanced 3D magnonic circuits with multiplexing capabilities.

Contribution

It presents the first design of a nanoscale vertical spin-wave directional coupler with high efficiency and magnetic field control, advancing 3D magnonic circuit integration.

Findings

Achieved over 99.5% coupling efficiency.

Demonstrated magnetic field control of operation.

Enabled multiplexing and demultiplexing of spin waves.

Abstract

The directional coupler is a fundamental element of wave-based circuits. The state of the art for the spin-wave directional couplers consists mostly of macroscopic waveguides or two-dimensional planar systems. In this Letter, we present the design of the nanoscale spin-wave vertical directional coupler with a very high efficiency exceeding 99.5%. We demonstrate that the operation of the coupler can be controlled by the magnitude of the external magnetic field. Moreover, it can perform multiplexing and demultiplexing of the spin-wave signal. Such a device ought to become an essential element of the three-dimensional magnonic circuits.