Picosecond ultralow-power switching device based on an antiferromagnet.

Developing an ultrafast and energy-efficient nonvolatile switching device may pose a strong impact on emerging computing architectures. However, processing speed has plateaued in the nanosecond regime, as further acceleration demands excessively large write power. We demonstrate ultralow power in picosecond switching using heterostructures of the antiferromagnet Mn3Sn and heavy metal tantalum, which exhibit spin-orbit torque switching by electrical pulses as short as 40 picoseconds. Power consumption in the picosecond regime is several orders of magnitude lower than in ferromagnetic counterparts owing to efficient angular momentum transfer. Compared with previously reported picosecond switching devices, our ultralow-power switching device realizes much less heating, higher endurance, and switching using photocurrent. These results pave the way to ultrafast nonvolatile memory and efficient optical-to-electrical conversion technology.