Current shunting effects in Cd₃As₂: a closer look at the topological-ferromagnet interface

Topological materials, such as Cd₃As₂, are of great importance for next-generation computing systems where energy efficiency is paramount. For example, in spin-orbit torque magnetic random-access memory (SOT-MRAM), topological materials generate the spin-orbit torque necessary for magnetization switching of an adjacent magnetic layer. Current shunting at the ferromagnet-topological material interface can be detrimental for spin generation and overall SOT efficiency.¹ Here, the current shunting effect is analyzed in permalloy- and gold-shunted Cd₃As₂ disk structures using angle-dependent magnetoresistance measurements. Shubnikov-de Haas oscillations and weak antilocalization effects are observed in the Cd₃As₂, and their presence is dampened upon incorporating a shunt onto the topological surface. Hakami-Larkin-Nagaoka and Tkachov-Hankiewicz models are used to evaluate the weak antilocalization.^2,3 We confirm the effects of current shunting, and discuss its detriment to the efficiency of spin-based devices.

References:

1. Tang, W., Liu, H., Li, Z., Pan, A. & Zeng, Y. Adv. Sci. 8, 2100847 (2021).

2. Hikami, S., Larkin, A. I. & Nagaoka, Y. Prog. Theor. Phys. 63, 707–710 (1980).

3. Tkachov, G. & Hankiewicz, E. M. Phys. Rev. B 84, 035444 (2011).