Local control of antiferromagnetic domains in Cr$_{2}$O$_{3}$*

We have used a Cr$_{2}$O$_{3}$/Pd/(Co/Pd)$_{3}$ exchange biased heterostructure to measure the spatial distribution of anti-ferromagnetic (AFM) domains in magnetoelectric AFM Cr$_{2}$O$_{3}$. The AFM Cr$_{2}$O$_{3}$ possesses a residual roughness insensitive surface magnetization below its N\'{e}el temperature (T$_{\mathrm{N}}$ 307K) This surface magnetization couples to the ferromagnetic material (Co/Pd) and results in exchange bias. Cooling the Cr$_{2}$O$_{3}$ from above its N\'{e}el temperature in different magnetization states of the ferromagnet results in the formation of AFM domains in Cr$_{2}$O$_{3}$. The AFM domains in the Cr$_{2}$O$_{3}$ were mapped by a spatial map of the exchange bias of the ferromagnet for the sample cooled in various remnant conditions of Co/Pd and at different temperatures. Local control of AFM domains was achieved by first, controlling the magnetization of Co/Pd multilayers and cooling below the Neel temperature, resulting in a single AFM domain, and then, subsequently writing a reversed AFM domain using the heat from a 6 mW focused laser beam. Scanning the laser beam allows for the writing of any domain pattern with a spatial resolution of 5 $\mu$m, limited only by the focusing optics.