Annika JOHANSSON
The (spin) Edelstein effect, also called current-induced spin polarization, provides charge-spin interconversion in systems with broken inversion symmetry: In pristine nonmagnetic materials, an external electric field can generate a charge current as well as a homogeneous spin density [1,2]. Thus, a finite magnetization can be generated and tuned exclusively electrically. Originally, the Edelstein effect has been discussed for two-dimensional Rashba systems at surfaces or interfaces.
In addition to this conventionally considered spin Edelstein effect, the electrons' orbital moments are also expected to provide a current-induced magnetization, which is called orbital Edelstein effect [3-6]. Thus, the magnetization induced electrically by the Edelstein effect can comprise contributions from both the spin and the orbital moments.
In this talk the spin and orbital Edelstein effects are discussed within a semiclassical Boltzmann approach. The theory is applied to Rashba systems as well as two-dimensional electron gases at oxide interfaces [7,8]. In the latter ones, the orbital Edelstein effect is predicted to exceed its spin counterpart by one order of magnitude. This finding can be understood by a band-resolved analysis of the spin and orbital Edelstein effects.
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[3] T. Yoda, T. Yokoyama, and S. Murakami, Sci. Rep. 5, 12024 (2015)
[4] T. Yoda, T. Yokoyama, and S. Murakami, Nano Lett. 18, 916 (2018)
[5] L. Salemi et al., Nat. Commun. 10, 5381 (2019)
[6] D. Hara, M. Bahramy, and S. Murakami, Phys. Rev. B 102, 184404 (2020)
[7] D. Vaz et al., Nat. Mater. 18, 1187 (2019)
[8] A. Johansson et al., Phys. Rev. Research 3, 013275 (2021)