Rashba-Edelstein Magnetoresistance in Metallic Heterostructures

Abstract

We report the observation of magnetoresistance originating from Rashba spin-orbit coupling (SOC) in a metallic heterostructure: the Rashba-Edelstein (RE) magnetoresistance. We show that the simultaneous action of the direct and inverse RE effects in a Bi/Ag/CoFeB trilayer couples current-induced spin accumulation to the electric resistance. The electric resistance changes with the magnetic-field angle, reminiscent of the spin Hall magnetoresistance, despite the fact that bulk SOC is not responsible for the magnetoresistance. We further found that, even when the magnetization is saturated, the resistance increases with increasing the magnetic-field strength, which is attributed to the Hanle magnetoresistance in this system.

Efficient charge-spin conversion and magnetization switching through the Rashba effect at topological-insulator/Ag interfaces

“…However, due to the bulk nature of SHE, a certain thickness of heavy metals is required to achieve a sufficient spin current density. Recently, Rashba induced charge-spin interconversions, with a higher efficiency than that from SHE, have been detected in Bi/Ag, α-Sn/Ag [7][8][9][10], LaAlO3/SrTiO3 [11]. On the other hand, the topological surface states (TSS) of topological insulators (TIs) are another interfacial mechanism for achieving efficient charge-to-spin conversion due to the strong spin orbit coupling (SOC) and inherent spinmomentum locking, despite of the inevitable bulk transport [3,4,[12][13][14][15][16][17].…”

Spin-current-induced magnetoresistance in trilayer structure with nonmagnetic metallic interlayer

“…For local magnetoresistance effects, such as the anisotropic magnetoresistance (AMR), its intrinsic magnetoresistance ratio MR int is related to MR in the multilayers via MR = R shunt MR int by considering parallel circuiting. 9,12) Obviously, Eq. (8) shows the dependence of MR int on G 0 r and Γ N , which is a distinct contribution from the shunting effect.…”

“…This difference can be attributed to the thickness dependence of the spin diffusion length due to that of the conductance and the spin memory loss effect at the interfaces. [25][26][27] The spin diffusion length decreases at a smaller thickness because of the interfacial scattering, 5,12,28) such that the decreased spin-current transmission reduces the SMR magnitude. Similarly, the spin memory loss effect reduces the spin current transmission through the interface.…”

“…This is due to the reduction in the spin accumulation for driving spin transfer torque. In addition to the SMR, we also calculated the recently observed Rashba-Edelstein magnetoresistance (REMR), caused by spin-charge conversion at the N=H interface, 12,15,23,24) because it is also affected by the spin accumulation reduction. The derived expression for the trilayer structure will be useful for understanding the spin-currentinduced magnetoresistance effects.…”

“…[1][2][3] Recently, a new type of magnetoresistance has been demonstrated, in which a spin current generated via spin-orbit coupling from an applied charge current plays a central role. [4][5][6][7][8][9][10][11][12] The generated spin current interacts with magnetization and magnetic field and changes its magnitude. 6,8,11,13) When the spin current is converted back to a charge current by spin-orbit coupling, 14,15) the spin-current transport modulates the conductivity of the system, and then gives rise to magnetoresistance.…”