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Parameters affecting the optically induced quench-switching of the antiferromagnetic CuMnAs

Publication at Faculty of Mathematics and Physics |


Antiferromagnetic materials represent a new area of research with potential applicability in spintronic devices. Compared to their ferromagnetic counterparts, antiferromagnetic materials exhibit faster dynamics, resiliency to the external magnetic field, and the absence of stray fields allowing for high integration density. Some functionalities are derived directly from their ferromagnetic counterparts, such as readout using anisotropic magnetoresistance or magnetic axis reorientation using current-induced spin-orbit torque Other are unique to antiferromagnets, such as recently discovered quenching into high resistivity states. The quench-switching effect is based on changes in the magnetic domain structure of the epitaxially grown thin antiferromagnetic films of CuMnAs. These changes can be induced by current or optical pulses, which bring the system to the vicinity of its Neél temperature. The subsequent fast cooling results in a quenched magnetic state characterized by increased resistivity. The change in the resistivity can reach tens of percent at room temperature and even up to a hundred percent at low temperatures, which exceeds the spin-orbit torque-based switching by two orders of magnitude [2]. The quench-switching signals exhibit a temperature-dependent relaxation with characteristic times in the range of seconds at room temperature, making it interesting for memory applications.

In this contribution, we explore differences in the response caused by changes in material parameters, such as CuMnAs layer thickness, device size, MBE growth conditions, and protective capping. The device performance is evaluated based on the observed amplitude of the quench-switching response. We also evaluate the durability of devices by monitoring the surface damage induced by the laser pulses.