In-situ imaging of memristive charge-density wave switching in EuTe4 devices

Switching to non‐thermal charge density wave (CDW) states has opened new avenues to access and control states far from equilibrium. Recently, we discovered a non‐thermal phase of the van der Waals layered semiconductor, EuTe4, that can be accessed with voltage pulses even at room temperature. The combination of room‐temperature non‐volatile operation and low‐voltage switching is highly attractive for energy‐efficient memory device applications. Early results suggest that the order defining the equilibrium and non‐equilibrium states is an interlayer CDW dimerization that manifests as half‐ordered diffraction peaks. Here, we propose to use X‐ray nano‐diffraction to spatially resolve the CDW switching of EuTe4 devices by following the respective diffraction patterns. Furthermore, nano‐diffraction imaging will also shed light on the switching mechanism, i.e. whether transition occurs via filamentary channels or sparse nucleation.