• Mitra, Chiranjib
• Manna, Subhadeep
• Pal, Pratap Kumar
• Barman, Anjan
• Mukhopadhyay, Suchetana

Abstract

<jats:title>Abstract</jats:title><jats:p>The rise of three-dimensional topological insulators as an attractive playground for the observation and control of various spin-orbit effects has ushered in the field of topological spintronics. To fully exploit their potential as efficient spin-orbit torque generators, it is crucial to investigate the efficiency of spin injection and transport at various topological insulator/ferromagnet interfaces, as characterized by their spin-mixing conductances and interfacial spin transparencies. Here, we use all-optical time-resolved magneto-optical Kerr effect magnetometry to demonstrate efficient room-temperature spin pumping in Sub/BiSbTe<jats:sub>1.5</jats:sub>Se<jats:sub>1.5</jats:sub>(BSTS)/Co<jats:sub>20</jats:sub>Fe<jats:sub>60</jats:sub>B<jats:sub>20</jats:sub>(CoFeB)/SiO<jats:sub>2</jats:sub> thin films. From the modulation of Gilbert damping with BSTS and CoFeB thicknesses, the spin-mixing conductances of the BSTS/CoFeB interface and the spin diffusion length in BSTS are determined. For BSTS thicknesses far exceeding the spin diffusion length, in the so-called “perfect spin sink” regime, we obtain an interfacial spin transparency as high as 0.9, promoting such systems as scintillating candidates for spin-orbitronic devices.</jats:p>

Topics

• impedance spectroscopy
• thin film
• interfacial