Temperature resolved spin-pumping in permalloy-bismuth selenide heterostructure

Abstract

This study explores the temperature-dependent magnetization dynamics in permalloy-topological insulator heterostructures using temperature-resolved ferromagnetic resonance. NiFe/Bi2Se3 heterostructures are compared to NiFe/Pt and NiFe/W systems to identify unique damping behaviors. This work uncovers an unprecedented damping profile in NiFe/Bi2Se3 at temperatures below 90 K, shedding light on the interplay between spin current backflow and spin reorientation transitions, mechanisms previously unexplored in this context. Additionally, significant differences in inhomogeneous linewidth broadening (ΔH0) and effective magnetization (Meff) are observed, further emphasizing the distinct spin dynamics in NiFe/Bi2Se3 compared to heavy metal-based heterostructures. The findings reveal that topological insulators like Bi2Se3 play a critical role in modulating spin-pumping processes, particularly through the Rashba effect and spin–orbit coupling. These results offer deeper insight into the mechanisms underlying magnetic damping and provide a foundation for the optimization of spintronic memory and logic devices. The findings provide a critical foundation for designing advanced spintronic devices, particularly for low-temperature applications in spin–orbit torque magnetic random-access memory and magnonic systems.