2022/10/11 by Rakshit Jain, Jain, Rakshit, Max Stanley +15 · 2 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum and electron transport phenomena #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2210.05636
openalex publication_date 2022/10/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We complete measurements of interconversions among the full triad of thermal gradients, charge currents, and spin currents in the topological insulator Bi2Se3 by quantifying the efficiency with which thermal gradients can generate transverse spin currents. We accomplish this by comparing the spin Nernst magneto-thermopower to the spin Hall magnesistance for bilayers of Bi2Se3/CoFeB. We find that Bi2Se3 does generate substantial thermally-driven spin currents. A lower bound for the ratio of spin current to thermal gradient is Js/∇x T = (4.9 ± 0.9) × 106 (ℏ/2e) A m-2 / K μm-1, and a lower bound for the magnitude of the spin Nernst ratio is -0.61 ± 0.11. The spin Nernst ratio for Bi2Se3 is the largest among all materials measured to date, 2-3 times larger compared to previous measurements for the heavy metals Pt and W.