Spin-transfer torque generated by a topological insulator

By A. Mellnik, Joon Sue Lee, Anthony Richardella, Jennifer L. Grab, Peter J. Mintun, Mark H. Fischer, Abolhassan Vaezi, A. Manchon, Eun-Ah Kim, N. Samarth and 1 more. Nature, 2014

1,325 citations recorded by the source corpus.

Magnetic devices are a leading contender for the implementation of memory and logic technologies that are non-volatile, that can scale to high density and high speed, and that do not wear out. However, widespread application of magnetic memory and logic devices will require the development of efficient mechanisms for reorienting their magnetization using the least possible current and power. There has been considerable recent progress in this effort; in particular, it has been discovered that spin–orbit interactions in heavy-metal/ferromagnet bilayers can produce strong current-driven torques on the magnetic layer, via the spin Hall effect in the heavy metal or the Rashba–Edelstein effect in the ferromagnet. In the search for materials to provide even more efficient spin–orbit-induced torques, some proposals have suggested topological insulators, which possess a surface state in which the effects of spin–orbit coupling are maximal in the sense that an electron’s spin orientation is fixed relative to its propagation direction. Here we report experiments showing that charge current flowing in-plane in a thin film of the topological insulator bismuth selenide (Bi2Se3) at room temperature can indeed exert a strong spin-transfer torque on an adjacent ferromagnetic permalloy (Ni81Fe19) thin film, with a direction consistent with that expected from the topological surface state. We find that the strength of the torque per unit charge current density in Bi2Se3 is greater than for any source of spin-transfer torque measured so far, even for non-ideal topological insulator films in which the surface states coexist with bulk conduction. Our data suggest that topological insulators could enable very efficient electrical manipulation of magnetic materials at room temperature, for memory and logic applications.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics

View Paper: https://www.semanticscholar.org/paper/c6efc21bd046956c357634d06ffa649e4c1781be

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

In Condensed Matter Physics

Citations in the corpus

Magnetization oscillations and waves driven by pure spin currents (2016, background): “In recent years, SHE has been demonstrated to enable efficient magnetization switching [47-50], control of domain walls [51-53], reduction of magnetic damping [46,54-64], suppression of magnetic noise [65], and excitation of high-frequency magnetization dynamics [66-78].”
Topological Photonic Quasicrystals: Fractal Topological Spectrum and Protected Transport (2016, background): “robust quantum Hall conductivity measurements [5], has potential applications in novel materials for topological quantum computing [6,7] and robust spintronic devices [8].”
Magnetism, symmetry and spin transport in van der Waals layered systems (2021, neutral): “Also, note that a microscopic calculation would automatically give such reduction, which can be used as a check, or simply one can use the symmetry to reduce calculation cost.”