Experimental demonstration of domain wall logic-in-memory through helicity-dependent optical effect and spin-orbit torque.

Spin-transfer or spin-orbit torque provides a powerful means of manipulating domain walls along magnetic wires, which paves the way towards the realization of devices based on domain walls for data storage or computing. However, the current density required to move domain walls is still too high. Here we experimentally demonstrate domain wall logic-in-memory by combining femtosecond laser and current pulses in perpendicularly magnetized Co/Ni wires. By adding circularly polarized laser excitations, we realize a direct detection of laser helicity and its nonvolatile storage into magnetic states, while the current density required to trigger domain wall motion due to spin-orbit torque can be reduced. In addition, the laser polarization offers a new lever to manipulate domain walls. Our energy-efficient approach highlights a new path towards low power optoelectronic domain wall logic and memory, which enables the development of new families of spintronic devices and perceptrons for learning combining photonics and electronics.