Heat-Assisted Magnetization Switching in Flexible Spin-Orbit Torque Devices.

Heat-assisted magnetic anisotropy engineering has been successfully used in selective magnetic writing and microwave amplification due to a large interfacial thermal resistance between the MgO barrier and the adjacent ferromagnetic layers. However, in spin-orbit torque devices, the writing current does not flow through the tunnel barrier, resulting in a negligible heating effect due to efficient heat dissipation. Here, we report a dramatically reduced switching current density of ∼2.59 MA/cm2 in flexible spin-orbit torque heterostructures, indicating a 98% decrease in writing energy consumption compared with that on a silicon substrate. The reduced driving current density is enabled by the dramatically decreased magnetic anisotropy due to Joule dissipation and the lower thermal conductivity of the flexible substrate. The large magnetic anisotropy could be fully recovered after the impulse, indicating retained high stability. These results pave the way for flexible spintronics with the otherwise incompatible advantages of low power consumption and high stability.